case study interview cheat sheet

Hacking the Case Interview

Looking for a case interview cheat sheet or study guide to help you prepare for your upcoming consulting interviews?

Download our Case Interview Cheat Sheet and Study Guide , which covers all of the most important things you need to know. If you are looking to read the case interview cheat sheet in plain text, we’ve included all of the text below.

This case interview cheat sheet covers:  

What is a case interview?

What do case interviews assess?

What is the structure of a case interview?

What are the common types of cases?

What formulas do you need to know for case interviews?

What numbers do you need to know for case interviews?

What are some case interview tips?

If you’re looking for a step-by-step shortcut to learn case interviews quickly, enroll in our case interview course . These insider strategies from a former Bain interviewer helped 30,000+ land consulting offers while saving hundreds of hours of prep time.

A case interview is a 30- to 45-minute exercise that places you in a hypothetical business situation in which you and the interviewer work together to develop a recommendation or answer to a business problem.

• How can Walmart increase its profitability?
• How can Nike increase customer retention?
• How should Apple price its new smartphone?

A case interview assesses five criteria:

1.   Logical, structured thinking : Can you structure complex problems and ideas in a clear and organized way?

2.  Analytical problem solving: Can you analyze and interpret data to draw the right conclusions?

3.  Business acumen : Do you have a strong understanding of business fundamentals and good business judgment?

4.  Communication skills : Can you communicate clearly, concisely, and articulately?

5.  Personality and cultural fit : Are you a good fit for the work culture of the firm you are interviewing with?

All case interviews follow seven major steps:

1.  Understand the case background : Take notes while the interviewer reads you the case information. Pay particularly close attention to the context, company, and objective.

2.  Ask  clarifying questions : If necessary, ask 1 – 3 questions to clarify the objective of the case, understand the company better, or understand an unfamiliar term.

3.  Structure a framework : Structure a framework to break down the complex business problem into simpler, smaller components. A framework is a tool that organizes different ideas into major categories. Present your framework to the interviewer. Make sure that your framework is MECE .

M utually E xclusive: None of the parts of your framework overlap with each other

C ollectively E xhaustive: All of the parts of the framework account for everything you need to know to solve the case with no major areas missing.

4.  Start the case : How the case will start depends on whether the case is an interviewer-led case or a candidate-led case .

Interviewer-led case : The interviewer will be steering and controlling the direction of the case. They will explicitly point you to which questions to answer.

Candidate-led case : You will be driving the direction of the case. You will propose what area of your framework to start in, what questions you want to answer, what analyses you want to do, and what the next step of the case is.

5.  Solve quantitative problems : There are three major types of quantitative problems you could be asked in case interviews.

Market sizing or estimation questions : You will be asked to calculate the size of a particular market or estimate a particular figure. You may need to make your own assumptions on what number to use or the interviewer may provide you with the data.

Profitability or breakeven questions : You will be asked to calculate the expected profitability of a company or investment decision. You could also be asked to calculate the conditions necessary for a company to break even .

Charts and graphs questions : You will be asked to interpret data from various charts or graphs . These can include bar charts, pie charts, line graphs, scatterplots, bubble charts, and waterfall charts.

6.  Answer qualitative questions : There are two major types of qualitative questions you could be asked in case interviews.

Brainstorming questions : You will be asked to brainstorm a list of ideas for a particular problem or question.

Business judgment questions : You will be asked for your opinion on a business issue or a strategic decision.

7. Deliver a recommendation : Present your recommendation and provide the major reasons that support it. Then, propose potential next steps that you would take if you had more time.

Profitability case : A company is experiencing a decline in profits or profitability and is trying to identify what is causing the decline and what they should do about it.

How to solve:  

• Identify the driver behind the decline in profitability, whether it is from a decline in revenue, increase in costs, or both
• Understand what is causing this by looking at customer needs, competitor moves, and market trends
• Identify ways to improve profitability

Growth strategy case : A company is trying to decide how to best grow its business.

• Determine whether the company is looking to grow organically or inorganically
• For organic growth, consider growth through existing revenue sources and new revenue sources
• For inorganic growth, consider potential acquisitions and partnerships

Market entry case : A company is trying to decide whether they should enter a particular new market.

• Determine whether the market is attractive
• Assess the competitive landscape
• Determine if the company has the capabilities to enter
• Estimate the expected profitability from entering

Merger & acquisition case : A company is trying to decide whether or not they should acquire or merge with a particular company.

• Determine whether the company is attractive
• Assess potential synergies and risks
• Estimate the financial implications

New product case : A company is trying to decide whether or not they should develop and launch a particular new product.

How to solve:

• Determine whether the market that the product targets is attractive
• Assess whether the product meets customer needs and is superior to competitor products
• Determine whether the company has the capabilities to successfully develop and launch the product
• Estimate the expected profitability from launching the product

Pricing case : A company is trying to decide the best way to price a particular product or service.

• Determine the cost to produce the product. This is your minimum price.
• Estimate the customer’s maximum willingness to pay by quantifying the value the product provides. This is your maximum price.
• Investigate the price that competitors are setting for similar products. This will help you determine the optimal price between your minimum and maximum price.

Profit Formulas

• Profit = Revenue – Costs
• Revenue = Quantity * Price
• Costs = Total Variable Costs + Total Fixed Costs
• Total Variable Costs = Quantity * Variable Costs
• Profit = (Price – Variable Costs) * Quantity – Total Fixed Costs

Investment Formulas

• Return on Investment = Profit / Investment Cost
• Payback Period = Investment Cost / Profit per Year

Operations Formulas

• Output = Rate * Time
• Utilization = Output / Maximum Output

Market Share Formulas

• Market Share = Company Revenue in the Market / Total Market Revenue
• Relative Market Share = Company Market Share / Largest Competitor’s Market Share

General Statistics

• Global population: 8 billion
• Average household size: 2.5 people per household
• Average life expectancy: 80 years

Country Population Statistics  

• United States: 320 million
• Canada: 40 million
• Mexico: 125 million
• Brazil: 200 million
• United Kingdom: 60 million
• Germany: 80 million
• France: 60 million
• China: 1.4 billion
• India: 1.4 billion
• Russia: 150 million
• Japan: 125 million
• Australia: 25 million

Tip #1 - Make sure you understand the business problem and objective : Answering or addressing the wrong business problem is the quickest way to fail a case interview.

Tip #2 - Don’t rely on using memorized frameworks : Interviewers can tell when you are regurgitating memorized information and not thinking critically.

Tip #3 - Structure your approach before doing any math calculations : This helps you avoid making unnecessary calculations or reaching a dead-end.

Tip #4 - Talk through your calculations out loud : This decreases the likelihood of making a mistake and helps the interviewer follow what you are doing

Tip #5 - Structure your answer to qualitative questions : Use a simple two-part framework such as internal/external, short-term/long-term, or economic/non-economic.

Tip #6 - Answer “so what?” after every question : Throughout the case, connect each of your answers back to the case objective. What implications does your answer have on the overall business problem?

Tip #7 - Have a firm recommendation : Do not have a flimsy recommendation that switches back and forth between two different recommendations. Pick one and provide support.

Tip #8 - Be 80/20 : You will not have time to answer every single question. Focus on the most important questions that have the greatest impact on your answer. This is the 80/20 principle which states that 80% of the outcome comes from 20% of your effort.

Tip #9 - Be coachable and easy to work with : Interviewers look for people that they would personally want to have on their team. Demonstrate that you would be a great teammate.

Tip #10 - Be enthusiastic : Interviewers want to hire candidates that love their job and will work hard. Displaying enthusiasm shows you are passionate about consulting and working at the firm.

Check out our complete list of case interview tips .

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Ace Your Interview: The Ultimate Consulting Case Interview Cheat Sheet

So, you’ve got your sights set on a consulting career, huh? You probably know that one of the biggest hurdles you’ll face is the consulting case interview. Consulting firms love using these interviews to put your problem-solving chops and communication and analytical skills to the test. But let’s be honest, prepping for a case interview can feel like climbing Mount Everest. Fear not, my friend! I’ve whipped up the ultimate consulting case interview cheat sheet to help you crush that interview like a pro. I’ve gone an extra step for you and included case interview examples with solutions too so you can prepare like a pro. 

Understanding the Consulting Case Interview

Ah, the consulting case interview – the make-or-break moment for aspiring consultants. In this unique interview format, you’ll be thrown a business problem and tasked with solving it. Get ready to ask those clarifying questions, dissect the issue, and lay out your top-notch recommendations.

The whole point of a consulting case interview is to put your critical and creative thinking, communication skills, and grace under pressure to the test. You’ll be judged on how well you can structure your analysis, pinpoint the crux of the matter, and whip up a logical, actionable solution. So, buckle up and bring your A-game!

The Importance of Preparation

Preparing for a case interview is essential if you want to succeed. The more you practice, the more comfortable and confident you will become. You should start by familiarizing yourself with the different types of case interviews and the frameworks that are commonly used. You should also practice solving case interviews and develop your own approach and style.

It is important to remember that the consulting case interview is not just about getting the right answer. It is also about demonstrating your problem-solving skills, your ability to work in a team, and your communication skills. You should practice presenting your ideas clearly and concisely, and you should be prepared to defend your recommendations.

The Consulting Case Interview Cheat Sheet

To help you prepare for your consulting case interview, I’ve put together a cheat sheet that includes a casing template sheet for you to use during your case interview as well as a breakdown of the key stages in a case interview. 

Remember, this is a tool, so use it in a way that best suits your needs and style.

When navigating the case interview, you should have 3 types of sheets: Your main sheet (page 1), your math/calculations sheet and your secondary sheets (page 2 onwards).

Main Sheet: Used at the start of your case. Contains the prompt notes, the objective, your framework, and any hypotheses you may have. You will also come back to this sheet at the end of the case to make your final recommendation.

This sheet should never be out of sight. If you are right-handed, put it to your right side when moving on. If you are left-handed, put it to the left.

Math/calculations sheet: This sheet is used for any calculations you have to conduct. Keep in mind, this sheet is not where you necessarily organize your math (create the formula). Rather, this is where you do your long addition, long division, your chaotic scribbling etc. The point of this sheet is to allow you to keep your other sheets clean.

Secondary sheets: These sheets are used during the case. You should use secondary sheets between the framework and the final recommendation stage of the case. In principle, one sheet should be used per section of the case . So, you may have 1, 2, 3, or even 4 secondary sheets in any given case, based on how many phases/sections the case contains.

How to organize and use your sheets: Keep your sheets organized by placing the first sheet with the framework and objective in sight, the math sheet aside, and tuck each subsequent secondary sheet under the previous one. This organization method helps you work through the case more effectively. 

The consulting case interview cheat sheet - Page 1

• Listen to the prompt: Take notes on the left side of your sheet, capturing the most important information using keywords or phrases, and shorthand.
• Resynthesize the prompt: Reiterate the prompt back to the interviewer in your own words, summarizing the most important information.
• Write down the company name and objective : As soon as you have the company name and objective, write them down at the top left and top center of your sheet, respectively.
• Ask clarifying questions: Understand the situation and narrow the scope of the case by asking questions about context, business model, objective, etc. Use the GOBTM acronym (Geography, Objective, Business model, Timing, and Market) if you’re stuck.
• (Optional) Write down initial hypotheses : If you have initial views on the case, you can note them down on the upper right side of your sheet (H1, H2, H3).
• Request time to gather your thoughts : Ask the interviewer for a couple of minutes to work on your framework.
• Develop and pitch your framework : Spend the requested time to create your framework, then present it to the interviewer.
• Proceed with the case: If you are in a candidate-led case, demonstrate case leadership by driving the case and asking questions. If you are in an interviewer-led case the interviewer will most likely navigate you to the next section of the case.

Throughout the case, ensure that you stay organized, maintain a clear objective, and adapt your approach as needed.

The consulting case interview cheat sheet - Page 2 (and onwards)

In an interviewer-led case, you’ll be asked questions and must respond accordingly. Whether the case is candidate-led or interviewer-led, it’s crucial to create additional sheets of paper to guide the case. Each time a new topic or section is introduced, use a new sheet. This helps you stay organized.

Each sheet should have a title summarizing the focus of that section. As information is given visually or verbally, record what’s relevant. If data is one-dimensional, write it on the left side. If it’s multi-dimensional, create a table to organize the data.

Capture the information quickly and if you miss something, make a note to clarify with the interviewer later. Organizing the data is crucial for figuring out where to go next. Also, use a separate sheet for messy math calculations.

When reaching a conclusion for a section, write it at the bottom of the sheet.

• Create additional sheets for each case section: As you move on to new topics or themes within the case, use a new sheet of paper to maintain organization and clarity.
• Organize your sheets effectively: Each sheet should have a title that summarizes the section you are working on. This will help you stay focused on the task at hand.
• Capture and categorize information: Information can come in two forms, visual or verbal. Write down relevant and important information as it comes to you. For one-dimensional information, write it on the left-hand side of the sheet. For multidimensional information, create a table to keep data organized.
• Track conclusions and takeaways: Write mini conclusions at the bottom of each sheet, summarizing the findings of each section. Box any relevant data or calculations.
• Stay organized throughout the case: Keep the first sheet in sight for easy reference, have a separate math sheet, and tuck subsequent sheets under each other. This setup allows for seamless transitions between sections and helps maintain a clear and organized workspace.
• Use page numbers to track progress: Assigning page numbers to each sheet helps you keep track of the different sections of the case and quickly refer back to previous findings.

General Tips and Tricks

To give you a leg up in acing your consulting case interview, I’ve put together a few handy tips and tricks to keep in mind during the big day:

• Listen carefully to the interviewer’s instructions and ask clarifying questions if necessary.
• Take time to structure your analysis and to identify key issues.
• Use my consulting case interview cheat sheet  to organize your thoughts and to present your ideas.
• Be confident and articulate when presenting your ideas.
• Be prepared to defend your recommendations and to consider alternative solutions.

Business case interview examples

To get you ready for your consulting case interview, I’ve assembled a few Business case interview examples that might pop up when you’re in the hot seat:

• How would you approach a market sizing problem for a new product?
• What are the key drivers of profitability in the airline industry?
• How would you analyze the customer experience for a retail store?
• What are the key factors to consider when pricing a new product?
• How would you optimize the operations of a manufacturing plant?

General Case Interview Examples with Solutions

To aid in your preparation for the consulting case interview, I’ve put together a few General Business case interview examples along with their solutions.

A retail company is considering expanding its product line to include a new line of clothing. What factors would you consider when making this decision?

When making a decision about expanding the product line, some of the factors to consider include market demand, competition, cost of production, and potential profits. You would need to analyze the target market for the new product line, the competitive landscape, and the potential costs and revenues associated with the new product line.

A pharmaceutical company is considering launching a new drug. How would you assess the potential profitability of this new drug?

When assessing the potential profitability of a new drug, some of the factors to consider include market demand, pricing, production costs, and competition. You would need to analyze the size of the target market, the competitive landscape, and the potential costs and revenues associated with launching the new drug.

Marketing Case Interview Case Interview Examples with Solutions

Marketing case interviews are used to test your ability to analyze a marketing problem and to develop a strategic recommendation. Here are some marketing Business case interview examples :

A restaurant chain is considering launching a new menu item. How would you assess the potential success of this new menu item?

When assessing the potential success of a new menu item, some of the factors to consider include market demand, pricing, production costs, and competition. You would need to analyze the size of the target market, the competitive landscape, and the potential costs and revenues associated with launching the new menu item.

A consumer goods company is considering launching a new product. How would you develop a marketing strategy for this new product?

When developing a marketing strategy for a new product, some of the factors to consider include the target market, the competitive landscape, and the marketing mix. You would need to analyze the needs and preferences of the target market, the strengths and weaknesses of the competition, and the optimal price, promotion, and distribution channels for the new product.

Operations Case Interview Examples with Solutions

Operations case interviews are used to test your ability to optimize a process or a system. Here are some operations Business case interview examples :

A manufacturing company is experiencing high scrap rates in its production process. How would you identify the root cause of this problem and develop a solution?

When identifying the root cause of high scrap rates, some of the factors to consider include the production process, the equipment, the materials, and the personnel. You would need to analyze the different steps in the production process, the quality of the materials, the maintenance of the equipment, and the training and supervision of the personnel.

A logistics company is experiencing high transportation costs. How would you optimize the transportation network to reduce costs?

When optimizing the transportation network, some of the factors to consider include the shipping routes, the modes of transportation, the scheduling, and the capacity. You would need to analyze the different shipping routes, the costs and benefits of different modes of transportation, the optimal scheduling of shipments, and the capacity constraints of the transportation network.

How to Ace Your Consulting Case Interview

To ace your consulting case interview, you need to be well prepared, confident, and articulate. 

• Practice, practice, practice . The more you practice, the more comfortable and confident you will become.
• Familiarize yourself with the different types of case interviews and the frameworks that are commonly used.
• Develop your own approach and style , and be prepared to adapt to different situations.
• Be confident and articulate when presenting your ideas, and be prepared to defend your recommendations.
• Stay calm and focused , and don’t be afraid to ask clarifying questions if necessary.

The consulting case interview can be a challenging and intimidating experience, but with the right preparation and practice, you can ace your interview and land your dream job in consulting. Use the consulting case interview cheat sheet , the Business case interview examples provided, and my course to develop your skills and confidence, and remember to stay calm, focused, and articulate during your interview. Good luck!

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Top 10 Case Interview Frameworks: Beginner Mistakes

“Which framework to use?” is probably among the most common questions popping up in a candidate’s mind when confronting a case.

This definitive guide will not only answer that question by introducing a few common frameworks, but also tell you HOW to use those frameworks more effectively during case interviews , and what pitfalls you should be aware of.

Table of Contents

Case interview frameworks – Overview

What are case interview frameworks.

Case interview frameworks are templates used to break down and solve business problems in case interviews. A framework can be off-the-shelf or highly customized for specific cases; it can also be tailored for certain functions/industries, or versatile enough for general problem-solving.

Common case interview frameworks include:

• Profitability Framework
• Business Situation Framework
• McKinsey M&A Framework
• 4P and 7P Frameworks
• Porter Five Forces Model

External vs Internal

Qualitative vs quantitative.

• Cost vs Benefits
• 2×2 Matrix (e.g.: BCG Growth-Share Matrix)

SWOT Analysis

All of these frameworks will be discussed later in this article.

During a case interview, you use consulting frameworks to break down the problem into smaller pieces through an issue tree and test each branch to see if the root-cause is in there. If a branch indeed contains the root-cause, you break it down further. Rinse and repeat until the root-cause is identified.

The big part of problem solving is about breaking down the problem in almost every step of the case.

What should I keep in mind when using consulting frameworks?

Templates should be treated as guidelines, and not strict rules . The same applies to case interview frameworks.

In the past, case interviews were much more predictable, and frameworks were more applicable. However, nowadays, case interviews are more similar to real business problems, where frameworks need a lot of customizations (you’ll see this word repeated a lot in this article) to be useful.

In fact, the whole consulting industry exists on the basis that consultants can customize theory to real, difficult business situations and produce positive results; nobody pays hundreds of thousands of dollars for them to recite a textbook – any college freshman can do as much.

That’s why in my Case Interview End-to-End Secrets Program , I don’t teach candidates to use frameworks – instead, the focus in on the fundamentals of case interview (problem-solving and business intuition) as well as the tips and techniques for instant performance improvement.

How can I use consulting frameworks effectively?

Here’s a problem with case interview beginners – they tend to go straight for the frameworks, before even knowing the basic mechanisms and principles of case interviews.

If you are one of those beginners, you must first grasp the basics of case interviews – the fundamentals of case interview problem-solving, the issue tree, and the MECE principle. I have written extensive, separate guides on these topics, but for starters, I advice you to read this Case Interview 101 comprehensive guide. 

Busting case interview framework myths

Myth 1: “the more frameworks i know, the better”.

Before we proceed with the popular frameworks in consulting and case interviews, here are four huge myths about frameworks you should steer clear of.

Spend your time learning to draw customized frameworks/ issue trees instead. Case interviews are getting progressively more realistic and less conforming to specific frameworks, so trying to memorize dozens of frameworks is of no use.

Additionally, you should attend to the qualitative side of things, to deeply absorb each framework and its use; skimming the surface will come back to bite you later.

Myth 2: “There must be a framework out there that fits this case”

Ready-made frameworks CANNOT cover all kinds of situations. Even regarding the ones covered, existing frameworks are often “okay-fit”, but not perfectly fit.

Just create a framework/issue tree yourself. Nobody deducts your points for not using a ready-made tool, they even give you points if you can customize it.

Myth 3: “The fancier the framework, the more impressed the interviewer”

You are definitely not wooing anyone by being fancy-schmancy here. Nobody cares about your shiny frame if it does not fit with the picture.

Consultants are very practical and result-oriented people ; what impresses them are candidates who really know what they are talking about, and actually produce good results.

What’s worse is that you also run the risk of appearing superficial; it’s not difficult for consultants with years of experience in the field to fully expose your bluffing. If that happens you may as well say goodbye to your chance of getting hired.

Myth 4: “Knowledge of frameworks is irrelevant in interviewer-led cases”

The assumption underlying this myth is that in interviewer-led cases , the candidate is not the driver of the case, so he or she does not need to actively break down the problem.

This cannot be further from the truth. Many questions in interviewer-led cases are about frameworks/issue trees (“What factors would you consider to solve this problem?”).

Even with other question types you still need to structure answers like a mini-case. Appropriate knowledge of frameworks, as such, is still a MUST.

Five common case interview frameworks

Profitability framework.

Profitability is the most common problem type in case interviews – that means the Profitability Framework is the first one to master for every prospective consultant. You have to absolutely nail it every time, there’s no way around it.

In case interviews, the Profitability Framework is used to mathematically break down the problem, before switching to more qualitative frameworks to devise solutions.

Most of the time, the framework looks like this:

What’s so good about it?

• Firstly, the Profitability Framework is a surefire way to draw a structured issue tree , as the framework is fundamentally MECE.
• Secondly, this framework is grounded in a simple mathematical basis – there’s no confusing qualitative concept to get lost in; heck, “revenues minus costs equal profits” is common sense. That’s why the Profitability Framework may as well be the easiest framework ever devised by humankind (or consultant-kind).

Are there any shortcomings I should be aware of?

• The Profitability Framework is generic; it may not reflect the nuances within the business enough to draw insightful conclusions. In businesses with wide price ranges, for example, just the total sales volume and average unit price do not tell you much.
• To extract more insightful information, either drill down quantitatively by introducing revenue/cost components not expressed in the basic framework (e.g.: revenue by product), or combine it with a qualitative framework.

Business situation framework

This is an extremely versatile template you can use in nearly every case, so make sure to learn it well. It’s not even a “should”, but a “must”.

In my video , I referred to the Business Situation Framework by the more tell-tale “3C & P”, based on it being derived from the famous 3C Framework. These four letters stand for “Company, Customers, Competitors, Products” – areas that the framework analyzes to yield solutions.

• The one big advantage of the Business Situation Framework is its comprehensiveness – covering four crucial internal and external factors in business strategy.
• This framework is quite flexible – you can use it as a template to draw customized issue trees for all kinds of cases. In our video, I demonstrated this by applying it to solve an HR problem.
• The very same comprehensiveness making the Business Situation Framework flexible, also makes it generic, hence the need for extensive modifications; in many cases (the one in our video, for example), not all four components are relevant.
• It is not a beginner-friendly framework – it does not explicitly state which factors to consider under each main branch; newbies often end up in awkward situations, not knowing what to do next and thinking in a bottom-up manner.

How do you avoid that situation then? I’m inclined to say “practice”, but that much is obvious. A less obvious solution is to equip yourself with some “ninja tips” by learning how each C and P is usually segmented, although again I have to emphasize that it’s vital to maintain a flexible mindset.

McKinsey M&A framework

I absolutely love this one because it works in almost every single M&A case.

There isn’t an official name for this framework, but since it is used by McKinsey consultants when confronting an M&A issue, I’d just call it the “McKinsey M&A Framework”.

The framework assesses a proposed M&A on three dimensions: the stand-alone value of each involving companies (values, strengths, weaknesses, etc.); their synergy, i.e. will the two companies combined be greater than the sum of its parts; and other factors, such as feasibility, culture, legal issues, etc.

• Firstly, the segmentation of stand-alone values and synergy is intrinsically MECE , helping the candidate cover all possibilities – every value of each company must fall into one of these categories.
• Secondly, the framework prompts the user to actively look for “Other factors”, increasing its suitability in unique circumstances.

Are there any shortcomings I should be aware of? 

• The framework does not tell you what to look for in each branch, especially in the “Other factors” branch; this ambiguity shouldn’t be too much of an issue for experienced consultants, but might prove troublesome for candidates.
• Again, as with the previous Business Situation Framework, having a few ninja tricks up your sleeves should help you avoid getting stuck, just don’t rely on them too much.

4P / 7P Marketing Mix

This one is perhaps the single most popular framework in marketing. In case interviews , the 4P/7P Framework is used to formulate and implement marketing strategies for the supposed client, such as in competitive situation or market entry cases.

The original Marketing Mix covers four aspects – Product, Price, Place, and Promotion – thus, “4P”; note that “Place” does not pertain to any physical location, but the channel used by the company to deliver its products to its customers.

When services are involved, the mix becomes 7P; the new additions are: People – those performing the services; Process – how those services are delivered to the customers; and Physical Evidence – the visible, physical clues about the services (think of decorations inside a restaurant).

• The best thing about this framework is its sole focus on marketing, making it very efficient for situations where marketing is the primary/only concern.
• Both the 4P and 7P variants are inherently narrow in scope; candidates must always be mindful that they are not covering the big picture with this framework. Only use them to develop marketing solutions.
• The 4P Marketing Mix, specifically, is not even comprehensive enough for some tangible products, such as high-end fashion, where People, Process and Physical Evidence make huge differences.

Porter’s five forces model

Porter’s Five Forces Model is best used when candidates ask for the case context surrounding the client company; this framework helps them know what to ask.

Michael Porter’s model analyzes how a company’s Competitors, Suppliers, Customers interact with it, as well as how New Entrants and Substitute Products might threaten its place in the industry; it produces a snapshot of the relative power the business holds over its industry environment.

• The model’s coverage of the industry landscape is extensive, giving the candidate a vivid picture of the industry surrounding and interacting with the client in the case.
• This framework doesn’t give a clear answer as to what to do – that is its primary drawback; Porter’s model is not “deep” enough to answer such questions.
• The framework is not comprehensive enough for certain industries where political and legal issues, as well as complementary products, are major factors.
• Another thing to keep in mind: Don’t ever analyze a company with the Five Forces Model – the Five Forces Model describes the industry around that business, not the business itself.

Five mini-frameworks – All-purpose tools

These powerful mini-frameworks are probably the most under-appreciated problem-solving tools ever existed.

Mini-frameworks, like the larger frameworks, are also templates to break down information in a top-down, organized fashion.

Unlike their big cousins, however, these are almost never a primary or upper-most component of an issue tree. Furthermore, while common case interview frameworks are, to varying degrees, business-oriented, mini-frameworks are universal.

In this section, I’ll introduce you to five mini-frameworks I find most helpful in consulting case interviews. They feature prominently as supplements for larger frameworks in candidate-led cases , or stand-alone templates to answer questions in interviewer-led cases.

This is a quick and easy method to segment information about a particular entity. The internal branch concerns the inside of the said entity, such as functions within a company; the external branch describes anything outside that entity.

Here’s an example of this mini-framework as an adjunct to the Profitability Framework:

South Sea – a company specializing in bottled sauces – has found its profits going down badly for the past few years. They want you to find out what’s causing the problem.

You split their profits into revenues and costs; from the data provided, it seems like a revenue problem so you’re going into that branch first. How do you proceed?

Here, a quick check can be performed by splitting the factors causing the decline into two groups – external and internal, then ask the interview if the declining profits are also experienced by other American airlines; “yes” suggests an external root cause while “no” suggests an internal one.

This method of segmentation is primarily used in evaluations. By dividing items into two MECE groups, it reduces confusion and minimizes the risk of missing an important item.

For illustration, we again look at the packaged food company in the previous example:

Turns out, South Sea has quite a few internal problems, in both their production and sales functions. Coincidentally, Wilhelm International is looking to acquire South Sea. Wilhelm controls an extensive distribution network, so the South Sea management is quite interested in the deal.

It’s your task to assess whether South Sea should accept Wilhelm’s offer of acquisition or not.

For this task, I recommend using the McKinsey M&A Framework to break down the analysis into three branches: (1) South Sea’s stand-alone value, (2) its possible synergy with Wilhelm International, and of course (3) there must be an “Other factors” branch as well.

Within each branch, it’s possible to group items into quantitative (profits, growth rates) and qualitative (brand name, capabilities). This combination makes the analysis more MECE , and easier to work with.

Costs vs Benefits

This decision-making tool is pretty straightforward – if the benefits outweigh the costs, you go with that option. Otherwise, you’d be better off keeping your money under the mattress.

The Costs-and-Benefits analysis is a somewhat-business-centric twist of the omnipotent Pros-and-Cons. Both of these approaches work even better with weights attached to each evaluating criterion to reflect its impact.

Now, let’s check up on South Sea:

The acquisition is proven to be beneficial for both sides. With the sales problem solved, South Sea turns its attention to the production issue. The management considers replacing some technologies to improve product quality, but they are not sure if the investment will pay off.

How do you know if the investment is worthwhile?

A simple Costs-and-Benefits breakdown would suffice.

For benefits you have the financial gains to consider, as well as non-financial benefits such as improved brand image (because surprisingly, people love good food!).

2×2 Matrix

The 2×2 Matrix is a decision-making tool where options are examined using two criteria, each of which forms an axis of the matrix.

How do you apply this matrix in South Sea’s case, then?

Wilhelm International, after acquiring South Sea, is looking to push the sales of South Sea’s products using its distribution chain. However, South Sea’s product portfolio is quite large, and each product line differs greatly in terms of sales, branding, and market growth rate.

You must select which product lines to focus on.

The 2×2 matrix most famous in the business world, and also suitable for this case, is BCG’s Growth-Share Matrix, which uses market growth rate and market share as decision-making criteria. The position of a business on this matrix suggests whether to invest in, maintain, or discard that business.

SWOT stands for Strengths, Weaknesses, Opportunities, Threats.

This mini-framework is seldom used in case interviews and consulting work because it’s very generic; however, for a quick and easy evaluation of a company’s positioning within the industry context, the SWOT analysis works just fine.

In most case interviews, this is where you usually turn to the Marketing Mix or the Business Situation frameworks, but even a SWOT analysis may yield some insights.

Other case interview frameworks

Besides the ones we have covered, there are some other case interview frameworks and mini-frameworks worth looking into:

• Six Forces Model: a variant of Porter’s Five Forces, introducing “Complementary Products” into the analysis.
• Lauterborn’s 4C Framework: a more consumer-oriented variant of the 4Ps, designed for niche marketing.
• McKinsey 7S Framework: a framework used in McKinsey for analyzing organizational effectiveness.
• Ansoff Matrix (Product-Market Grid): a 2×2 matrix, designed for product-market strategizing.

Applying frameworks in case interviews

Here are my five rules to effectively implement frameworks in case interviews; if you follow these rules closely, you will absolutely nail the case.

Of these five rules, the first three are about getting the right framework, while the last two are about looking smart during interviews.

• Getting to know the case: “If you know your case and know your frameworks, you need not fear the result of a hundred case interviews” – always gather as much information as possible before and when you draw your issue tree .
• Bending the frameworks: don’t ever bend reality to your frameworks; bend your frameworks to reality; remove, add, or modify elements if necessary.
• Allying with the interviewer: ask the interviewer to help you break down the problem if you get stuck . How do you get him on your side then? By displaying overwhelming consulting traits .
• 13 Reasons why: “Why do you break down the problem that way?”, “Why do you want this piece of data?” – explain all your questions and decisions as if you stand before the US Congress, and before the interviewer asks you; consultants love accountable people.
• Frameworks-which-must-not-be-named: don’t ever explicitly say the names of the frameworks (“I’m going to use the McKinsey M&A Framework”); you would sound very rigid, bookish, or worse, arrogant; consultants don’t like big words without substance.

I’ll give you a brief case sample to see how these rules work in practice:

Interviewer: Our client today is a restaurant called BurgerQueen, located on US Highway 66. The restaurant has found its profits going down last year, your task is to find out the problem and give them a solution.

Candidate: Thank you for the very interesting case, I’m quite excited to solve it. Now, before we dive in,, I would like to playback the case to make sure that we perceive it the same way, ask a few questions for clarification, then announce my approach. Does that sound good to you?

Interviewer: Okay, carry on.

Candidate: Well, let’s see… Our client is a restaurant, on a highway, specifically, Route 66. Their profits have been going bad. I am to find the cause, and solve the problem. Am I getting it right?

Interviewer: Yes, you’re right.

Candidate: Thank you. Now I’d like to clarify the case, so I have 3 questions:

(1) I assume from the name that our client focuses on burgers, and probably other kinds of fast food. Am I right? (2) Does this restaurant have a specific target customer, like truck drivers? And (3) Is it part of a rest stop?

Interviewer: I’ll answer your questions: they sell burgers, but there are many other dishes as well – although mainly fast food; the restaurant does not have a specific target customer, their customers are drivers and travelers on the highway in general; they are part of a rest stop, but they do not own other facilities in the stop, just the restaurant.

Candidate: Great, thanks for the information. Now that we’re all on the same page, and the case has been clarified, I’d like to inform you of my approach. To eliminate this problem in the long run, I think it’s best to break down the problem using an issue tree, isolate the root cause in one of the branches, and gather information until we can draw an actionable solution. Is that approach okay to you?

Interviewer: That sounds good. Continue.

Candidate: To analyze this problem, I’m breaking it down into two sides: Revenues and Costs. Unless we have information pointing in the other direction, I’ll first hypothesize that the problem comes from the revenue side. May I have some data on the restaurant’s revenue during the past year, to prove this hypothesis?

Interviewer: Well, this year their revenue went down by about 40%, but the monthly revenues followed the same pattern as the previous year.

Candidate: Thank you for the data. It’s quite a sudden decrease. I think we can confirm that at least part of this problem comes from the revenue side; I’ll come back to check on the cost side later, now I’d like to go deeper into this revenue branch. Is that okay to you?

Interviewer: Okay, go on.

Candidate: Usually, revenue is divided into sales volume and unit price, but it wouldn’t make much sense for a restaurant with many different items on the menu. My limited knowledge of the food service industry is not exactly helpful, so to draw a more spot-on issue tree, may I ask how they segment the revenue in this restaurant?

Interviewer: Okay, here’s the answer: another way they segment the revenue in a restaurant is into “number of customers” and “average ticket size”, the latter being the purchase value per customer.

What are the key takeaways here?

You can see the candidate tried to gather information on the case through the playback and clarification steps; as a result, he correctly decided that the Profitability Framework is suitable for this case.

However, he quickly found out that the conventional “revenue = volume x price” isn’t too insightful, so he knew he needed to bend the framework.

Unable to find a good way to segment, he asked for help from the interviewer – note how he showed a relevant purpose for the request, and demonstrated that he at least made an effort – these are what we call “consulting traits”.

You should also notice that throughout this brief opening part, the candidate never explicitly mentioned the name of the Profitability Framework, and he always explained his choices before being asked.

Let's practice!

EXERCISE: Develop a 2-level issue tree for this case

The Megapolis City Council is looking to solve a major problem in the city’s traffic – for the last decade, the number of traffic accidents has been rising steadily.

Which factors would you look at, to tackle this problem?

This question apparently can not be answered using any aforementioned framework. In real life, consultants rarely use pre-defined frameworks to solve their client’s issues. Rather, they create unique frameworks based on the MECE principle specific to their problems.

There are few things you should bear in mind to shortcut the way to your own framework:

• Be as MECE or structural as possible.
• Use the issue tree to sketch your framework.
• Break down your problem in a top-down style.

Practice this step-by-step with any real-life issues.

Want to learn more? Join millions of others on our Case Interview End-to-end Secret Program .

Then, to receive personalized practice, you can book a coaching session with our experienced coaches from McKinsey, BCG, or Bain. They will quickly identify your areas of improvement and help you ace your interview.

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Profitability is the most common interview case types in MBB & you will most likely face one. Thus profitability framework is a method to solve profit problems

A case interview is where candidates is asked to solve a business problem. They are used by consulting firms to evaluate problem-solving skill & soft skills

An issue tree is a breakdown method of problems into multiple levels of subsets. It will isolates the root causes and ensures impactful solutions to the problem

• Case Interview: A comprehensive guide
• Pyramid Principle
• Hypothesis driven structure
• Fit Interview
• Consulting math
• The key to landing your consulting job
• What is a case interview?
• Types of case interview
• How to solve cases with the Problem-Driven Structure?
• What to remember in case interviews
• Case examples or building blocks?
• How do I prepare for case interviews
• Interview day tips
• How we can help

1. The key to landing your consulting job.

Case interviews - where you are asked to solve a business case study under scrutiny - are the core of the selection process right across McKinsey, Bain and BCG (the “MBB” firms). This interview format is also used pretty much universally across other high-end consultancies; including LEK, Kearney, Oliver Wyman and the consulting wings of the “Big Four”.

If you want to land a job at any of these firms, you will have to ace multiple case interviews.

It is increasingly likely that you will also have to solve online cases given by chatbots. You might need to pass these either before making it to interview or be asked to sit them alongside first round interviews.

Importantly, case studies aren’t something you can just wing . Firms explicitly expect you to have thoroughly prepared and many of your competitors on interview day will have been prepping for months.

Don’t worry though - MCC is here to help!

This article will take you through a full overview of everything you’ll need to know to do well, linking to more detailed articles and resources at each stage to let you really drill down into the details.

As well as traditional case interviews, we’ll also attend to the new formats in which cases are being delivered and otherwise make sure you’re up to speed with recent trends in this overall part of consulting recruitment.

Before we can figure out how to prepare for a case interview, though, we will first have to properly understand in detail what exactly you are up against. What format does a standard consulting case interview take? What is expected of you? How will you be assessed?

Let's dive right in and find out!

Professional help

Before going further, if this sounds like a lot to get your head around on your own, don't worry - help is available!

Our Case Academy course gives you everything you need to know to crack cases like a pro:

Case Academy Course

To put what you learn into practice (and secure some savings in the process) you can add mock interview coaching sessions with expereinced MBB consultants:

Coaching options

And, if you just want an experienced consultant to take charge of the whole selection process for you, you can check out our comprehensive mentoring programmes:

Explore mentoring

Now, back to the article!

2. What is a case interview?

Before we can hope to tackle a case interview, we have to understand what one is.

In short, a case interview simulates real consulting work by having you solve a business case study in conversation with your interviewer.

This case study will be a business problem where you have to advise a client - that is, an imaginary business or similar organisation in need of guidance.

You must help this client solve a problem and/or make a decision. This requires you to analyse the information you are given about that client organisation and figure out a final recommendation for what they should do next.

Business problems in general obviously vary in difficulty. Some are quite straightforward and can be addressed with fairly standard solutions. However, consulting firms exist precisely to solve the tough issues that businesses have failed to deal with internally - and so consultants will typically work on complex, idiosyncratic problems requiring novel solutions.

Some examples of case study questions might be:

• How much would you pay for a banking licence in Ghana?
• Estimate the potential value of the electric vehicle market in Germany
• How much gas storage capacity should a UK domestic energy supplier build?

Consulting firms need the brightest minds they can find to put to work on these important, difficult projects. You can expect the case studies you have to solve in interview, then, to echo the unique, complicated problems consultancies deal with every day. As we’ll explain here, this means that you need to be ready to think outside the box to figure out genuinely novel solutions.

2.1. Where are case interviews in the consulting selection process?

Not everyone who applies to a consulting firm will have a case interview - far from it!

In fact, case interviews are pretty expensive and inconvenient for firms to host, requiring them to take consultants off active projects and even fly them back to the office from location for in-person interviews (although this happens less frequently now). Ideally, firms want to cut costs and save time by narrowing down the candidate pool as much as possible before any live interviews.

As such, there are some hoops to jump through before you make it to interview rounds.

Firms will typically eliminate as much as 80% of the applicant pool before interviews start . For most firms, 50%+ of applicants might be cut based on resumes, before a similar cut is made on those remaining based on aptitude tests. McKinsey currently gives their Solve assessment to most applicants, but will use their resulting test scores alongside resumes to cut 70%+ of the candidate pool before interviews.

You'll need to be on top of your game to get as far as an interview with a top firm. Getting through the resume screen and any aptitude tests is an achievement in itself! Also we need to note that the general timeline of an application can differ depending on a series of factors, including which position you apply, your background, and the office you are applying to. For example, an undergraduate applying for a Business Analyst position (the entry level job at McKinsey) will most likely be part of a recruitment cycle and as such have pretty fixed dates when they need to sit the pre-screening test, and have the first and second round interviews (see more on those below). Conversely, an experienced hire will most likely have a much greater choice of test and interview dates as well as more time at their disposal to prepare.

For readers not yet embroiled in the selection process themselves, let’s put case interviews in context and take a quick look at each stage in turn. Importantly, note that you might also be asked to solve case studies outside interviews as well…

2.1.1. Application screen

It’s sometimes easy to forget that such a large cut is made at the application stage. At larger firms, this will mean your resume and cover letter is looked at by some combination of AI tools, recruitment staff and junior consulting staff (often someone from your own university).

Only the best applications will be passed to later stages, so make sure to check out our free resume and cover letter guides, and potentially get help with editing , to give yourself the best chance possible.

2.1.2. Aptitude tests and online cases

This part of the selection process has been changing quickly in recent years and is increasingly beginning to blur into the traditionally separate case interview rounds.

In the past, GMAT or PST style tests were the norm. Firms then used increasingly sophisticated and often gamified aptitude tests, like the Pymetrics test currently used by several firms, including BCG and Bain, and the original version of McKinsey’s Solve assessment (then branded as the Problem Solving Game).

Now, though, there is a move towards delivering relatively sophisticated case studies online. For example, McKinsey has replaced half the old Solve assessment with an online case. BCG’s Casey chatbot case now directly replaces a live first round case interview, and in the new era of AI chatbots, we expect these online cases to quickly become more realistic and increasingly start to relieve firms of some of the costs of live interviews.

Our consultants collectively reckon that, over time, 50% of case interviews are likely to be replaced with these kinds of cases . We give some specific advice for online cases in section six. However, the important thing to note is that these are still just simulations of traditional case interviews - you still need to learn how to solve cases in precisely the same way, and your prep will largely remain the same.

2.1.3. Rounds of Interviews

Now, let’s not go overboard with talk of AI. Even in the long term, the client facing nature of consulting means that firms will have live case interviews for as long as they are hiring anyone. And in the immediate term, case interviews are still absolutely the core of consulting selection.

Before landing an offer at McKinsey, Bain, BCG or any similar firm, you won’t just have one case interview, but will have to complete four to six case interviews, usually divided into two rounds, with each interview lasting approximately 50-60 minutes .

Being invited to first round usually means two or three case interviews. As noted above, you might also be asked to complete an online case or similar alongside your first round interviews.

If you ace first round, you will be invited to second round to face the same again, but more gruelling. Only then - after up to six case interviews in total, can you hope to receive an offer.

2.2. Differences between first and second round interviews

Despite interviews in the first and second round following the same format, second/final round interviews will be significantly more intense . The seniority of the interviewer, time pressure (with up to three interviews back-to-back), and the sheer value of the job at stake will likely make a second round consulting case interview one of the most challenging moments of your professional life.

There are three key differences between the two rounds:

• Time Pressure : Final round case interviews test your ability to perform under pressure, with as many as three interviews in a row and often only very small breaks between them.
• Focus : Since second round interviewers tend to be more senior (usually partners with 12+ years experience) and will be more interested in your personality and ability to handle challenges independently. Some partners will drill down into your experiences and achievements to the extreme. They want to understand how you react to challenges and your ability to identify and learn from past mistakes.
• Psychological Pressure: While case interviews in the first round are usually more focused on you simply cracking the case, second round interviewers often employ a "bad cop" strategy to test the way you react to challenges and uncertainty.

2.3. What skills do case interviews assess?

Reliably impressing your interviewers means knowing what they are looking for. This means understanding the skills you are being assessed against in some detail.

Overall, it’s important always to remember that, with case studies, there are no strict right or wrong answers. What really matters is how you think problems through, how confident you are with your conclusions and how quick you are with the back of the envelope arithmetic.

The objective of this kind of interview isn’t to get to one particular solution, but to assess your skillset. This is even true of modern online cases, where sophisticated AI algorithms score how you work as well as the solutions you generate.

If you visit McKinsey , Bain and BCG web pages on case interviews, you will find that the three firms look for very similar traits, and the same will be true of other top consultancies.

Broadly speaking, your interviewer will be evaluating you across five key areas:

2.1.1.One: Probing mind

Showing intellectual curiosity by asking relevant and insightful questions that demonstrate critical thinking and a proactive nature. For instance, if we are told that revenues for a leading supermarket chain have been declining over the last ten years, a successful candidate would ask:

“ We know revenues have declined. This could be due to price or volume. Do we know how they changed over the same period? ”

This is as opposed to a laundry list of questions like:

• Did customers change their preferences?
• Which segment has shown the decline in volume?
• Is there a price war in the industry?

2.1.2. Structure

Structure in this context means structuring a problem. This, in turn, means creating a framework - that is, a series of clear, sequential steps in order to get to a solution.

As with the case interview in general, the focus with case study structures isn’t on reaching a solution, but on how you get there.

This is the trickiest part of the case interview and the single most common reason candidates fail.

We discuss how to properly structure a case in more detail in section three. In terms of what your interviewer is looking for at high level, though, key pieces of your structure should be:

• Proper understanding of the objective of the case - Ask yourself: "What is the single crucial piece of advice that the client absolutely needs?"
• Identification of the drivers - Ask yourself: "What are the key forces that play a role in defining the outcome?"

Our Problem Driven Structure method, discussed in section three, bakes this approach in at a fundamental level. This is as opposed to the framework-based approach you will find in older case-solving

Focus on going through memorised sequences of steps too-often means failing to develop a full understanding of the case and the real key drivers.

At this link, we run through a case to illustrate the difference between a standard framework-based approach and our Problem Driven Structure method.

2.1.3. Problem Solving

You’ll be tested on your ability to identify problems and drivers, isolate causes and effects, demonstrate creativity and prioritise issues. In particular, the interviewer will look for the following skills:

• Prioritisation - Can you distinguish relevant and irrelevant facts?
• Connecting the dots - Can you connect new facts and evidence to the big picture?
• Establishing conclusions - Can you establish correct conclusions without rushing to inferences not supported by evidence?

2.1.4. Numerical Agility

In case interviews, you are expected to be quick and confident with both precise and approximated numbers. This translates to:

• Performing simple calculations quickly - Essential to solve cases quickly and impress clients with quick estimates and preliminary conclusions.
• Analysing data - Extract data from graphs and charts, elaborate and draw insightful conclusions.
• Solving business problems - Translate a real world case to a mathematical problem and solve it.

Our article on consulting math is a great resource here, though the extensive math content in our MCC Academy is the best and most comprehensive material available.

2.1.5. Communication

Real consulting work isn’t just about the raw analysis to come up with a recommendation - this then needs to be sold to the client as the right course of action.

Similarly, in a case interview, you must be able to turn your answer into a compelling recommendation. This is just as essential to impressing your interviewer as your structure and analysis.

Consultants already comment on how difficult it is to find candidates with the right communication skills. Add to this the current direction of travel, where AI will be able to automate more and more of the routine analytic side of consulting, and communication becomes a bigger and bigger part of what consultants are being paid for.

So, how do you make sure that your recommendations are relevant, smart, and engaging? The answer is to master what is known as CEO-level communication .

This art of speaking like a CEO can be quite challenging, as it often involves presenting information in effectively the opposite way to how you might normally.

To get it right, there are three key areas to focus on in your communications:

• Top down : A CEO wants to hear the key message first. They will only ask for more details if they think that will actually be useful. Always consider what is absolutely critical for the CEO to know, and start with that. You can read more in our article on the Pyramid Principle .
• Concise : This is not the time for "boiling the ocean" or listing an endless number possible solutions. CEOs, and thus consultants, want a structured, quick and concise recommendation for their business problem, that they can implement immediately.
• Fact-based : Consultants share CEOs' hatred of opinions based on gut feel rather than facts. They want recommendations based on facts to make sure they are actually in control. Always go on to back up your conclusions with the relevant facts.

Being concise and to the point is key in many areas, networking being one for them. For more detail on all this, check out our full article on delivering recommendations .

Prep the right way

3. types of case interview.

While most case interviews share a similar structure, firms will have some differences in the particular ways they like to do things in terms of both the case study and the fit component.

As we’ll see, these differences aren’t hugely impactful in terms of how you prepare. That said, it's always good to know as much as possible about what you will be going up against.

3.1. Different case objectives

A guiding thread throughout this article and our approach in general will be to treat each case as a self-contained problem and not try to pigeonhole it into a certain category. Having said that, there are of course similarities between cases and we can identify certain parameters and objectives.

Broadly speaking, cases can be divided into issue-based cases and strategic decision cases. In the former you will be asked to solve a certain issue, such as declining profits, or low productivity whereas in the latter you will be ask whether your client should or should not do something, such as enter a specific market or acquire another company. The chart below is a good breakdown of these different objectives:

3.2. How do interviewers craft cases

While interviewers will very likely be given a case bank to choose from by their company, a good number of them will also choose to adapt the cases they would currently be working on to an interview setting. The difference is that the latter cases will be harder to pigeonhole and apply standard frameworks to, so a tailored approach will be paramount.

If you’ve applied for a specific practice or type of consulting - such as operational consulting, for example - it’s very likely that you will receive a case geared towards that particular area alongside a ‘generalist’ consulting case (however, if that’s the case, you will generally be notified). The other main distinction when it comes to case interviews is between interviewer-led and candidate-led.

3.3. Candidate-led cases

Most consulting case interview questions test your ability to crack a broad problem, with a case prompt often going something like:

" How much would you pay to secure the rights to run a restaurant in the British Museum? "

You, as a candidate, are then expected to identify your path to solve the case (that is, provide a structure), leveraging your interviewer to collect the data and test your assumptions.

This is known as a “candidate-led” case interview and is used by Bain, BCG and other firms. From a structuring perspective, it’s easier to lose direction in a candidate-led case as there are no sign-posts along the way. As such, you need to come up with an approach that is both broad enough to cover all of the potential drivers in a case but also tailored enough to the problem you are asked to solve. It’s also up to you to figure out when you need to delve deeper into a certain branch of the case, brainstorm or ask for data. The following case from Bain is an excellent example on how to navigate a candidate-led case.

3.4. Interviewer-led cases

This type of case - employed most famously by McKinsey - is slightly different, with the interviewer controlling the pace and direction of the conversation much more than with other case interviews.

At McKinsey, your interviewer will ask you a set of pre-determined questions, regardless of your initial structure. For each question, you will have to understand the problem, come up with a mini structure, ask for additional data (if necessary) and come to the conclusion that answers the question. This more structured format of case also shows up in online cases by other firms - notably including BCG’s Casey chatbot (with the amusing result that practising McKinsey-style cases can be a great addition when prepping for BCG).

Essentially, these interviewer-led case studies are large cases made up of lots of mini-cases. You still use basically the same method as you would for standard (or candidate-led) cases - the main difference is simply that, instead of using that method to solve one big case, you are solving several mini-cases sequentially. These cases are easier to follow as the interviewer will guide you in the right direction. However, this doesn’t mean you should pay less attention to structure and deliver a generic framework! Also, usually (but not always!) the first question will ask you to map your approach and is the equivalent of the structuring question in candidate-led cases. Sometimes, if you’re missing key elements, the interviewer might prompt you in the right direction - so make sure to take those prompts seriously as they are there to help you get back on track (ask for 30 seconds to think on the prompt and structure your approach). Other times - and this is a less fortunate scenario - the interviewer might say nothing and simply move on to the next question. This is why you should put just as much thought (if not more) into the framework you build for interviewer-led cases , as you may be penalized if you produce something too generic or that doesn’t encompass all the issues of the case.

3.5. Case and fit

The standard case interview can be thought of as splitting into two standalone sub-interviews. Thus “case interviews” can be divided into the case study itself and a “fit interview” section, where culture fit questions are asked.

This can lead to a bit of confusion, as the actual case interview component might take up as little as half of your scheduled “case interview”. You need to make sure you are ready for both aspects.

To illustrate, here is the typical case interview timeline:

• First 15-30 minutes: Fit Interview - with questions assessing your motivation to be a consultant in that specific firm and your traits around leadership and teamwork. Learn more about the fit interview in our in-depth article here .
• Next 30-40 minutes: Case Interview - solving a case study
• Last 5 minutes: Fit Interview again - this time focussing on your questions for your interviewer.

Both the Case and Fit interviews play crucial roles in the finial hiring decision. There is no “average” taken between case and fit interviews: if your performance is not up to scratch in either of the two, you will not be able to move on to the next interview round or get an offer.

NB: No case without fit

Note that, even if you have only been told you are having a case interview or otherwise are just doing a case study, always be prepared to answer fit questions. At most firms, it is standard practice to include some fit questions in all case interviews, even if there are also separate explicit fit interviews, and interviewers will almost invariably include some of these questions around your case. This is perfectly natural - imagine how odd and artificial it would be to show up to an interview, simply do a case and leave again, without talking about anything else with the interviewer before or after.

3.5.1 Differences between firms

For the most part, a case interview is a case interview. However, firms will have some differences in the particular ways they like to do things in terms of both the case study and the fit component.

3.5.2. The McKinsey PEI

McKinsey brands its fit aspect of interviews as the Personal Experience Interview or PEI. Despite the different name, this is really much the same interview you will be going up against in Bain, BCG and any similar firms.

McKinsey does have a reputation for pushing candidates a little harder with fit or PEI questions , focusing on one story per interview and drilling down further into the specific details each time. We discuss this tendency more in our fit interview article . However, no top end firm is going to go easy on you and you should absolutely be ready for the same level of grilling at Bain, BCG and others. Thus any difference isn’t hugely salient in terms of prep.

3.6. What is different in 2023?

For the foreseeable future, you are going to have to go through multiple live case interviews to secure any decent consulting job. These might increasingly happen via Zoom rather than in person, but they should remain largely the same otherwise.

However, things are changing and the rise of AI in recent months seems pretty much guaranteed to accelerate existing trends.

Even before the explosive development of AI chatbots like ChatGPT we have seen in recent months, automation was already starting to change the recruitment process.

As we mentioned, case interviews are expensive and inconvenient for firms to run . Ideally, then, firms will try to reduce the number of interviews required for recruitment as far as possible. For many years, tests of various kinds served to cut down the applicant pool and thus the number of interviews. However, these tests had a limited capacity to assess candidates against the full consulting skillset in the way that case interviews do so well.

More recently, though, the development of online testing has allowed for more and more advanced assessments. Top consulting firms have been leveraging screening tests that better and better capture the same skillset as case interviews. Eventually this is converging on automated case studies. We see this very clearly with the addition of the Redrock case to McKinsey’s Solve assessment.

As these digital cases become closer to the real thing, the line between test and interview blurs. Online cases don’t just reduce the number of candidates to interview, but start directly replacing interviews.

Case in point here is BCG’s Casey chatbot . Previously, BCG had deployed less advanced online cases and similar tests to weed out some candidates before live case interviews began. Now, though, Casey actually replaces one first round case interview.

Casey, at time of writing, is still a relatively “basic” chatbot, basically running through a pre-set script. The Whatsapp-like interface does a lot of work to make it feel like one is chatting to a “real person” - the chatbot itself, though, cannot provide feedback or nudges to candidates as would a human interviewer.

We fully expect that, as soon as BCG and other firms can train a truer AI, these online cases will become more widespread and start replacing more live interviews.

We discuss the likely impacts of advanced AI on consulting recruitment and the industry more broadly in our blog.

Here, though, the real message is that you should expect to run into digital cases as well as traditional case interviews.

Luckily, despite any changes in specific format, you will still need to master the same fundamental skills and prepare in much the same way.

We’ll cover a few ways to help prepare for chatbot cases in section four. Ultimately, though, firms are looking for the same problem solving ability and mindset as a real interviewer. Especially as chatbots get better at mimicking a real interviewer, candidates who are well prepared for case cracking in general should have no problem with AI administered cases.

3.6.1. Automated fit interviews

Analogous to online cases, in recent years there has been a trend towards automated, “one way” fit interviews, with these typically being administered for consultancies by specialist contractors like HireVue or SparkHire.

These are kind of like Zoom interviews, but if the interviewer didn’t show up. Instead you will be given fit questions to answer and must record your answer in your computer webcam. Your response will then go on to be assessed by an algorithm, scoring both what you say and how you say it.

Again, with advances in AI, it is easy to imagine these automated interviews going from fully scripted interactions, where all candidates are asked the same list of questions, to a more interactive experience. Thus, we might soon arrive at a point where you are being grilled on the details of your stories - McKinsey PEI style - but by a bot rather than a human.

We include some tips on this kind of “one way” fit interview in section six here.

4. How to solve cases with the Problem-Driven Structure?

If you look around online for material on how to solve case studies, a lot of what you find will set out framework-based approaches. However, as we have mentioned, these frameworks tend to break down with more complex, unique cases - with these being exactly the kind of tough case studies you can expect to be given in your interviews.

To address this problem, the MyConsultingCoach team has synthesized a new approach to case cracking that replicates how top management consultants approach actual engagements.

MyConsultingCoach’s Problem Driven Structure approach is a universal problem solving method that can be applied to any business problem , irrespective of its nature.

As opposed to just selecting a generic framework for each case, the Problem Driven Structure approach works by generating a bespoke structure for each individual question and is a simplified version of the roadmap McKinsey consultants use when working on engagements.

The canonical seven steps from McKinsey on real projects are simplified to four for case interview questions, as the analysis required for a six-month engagement is somewhat less than that needed for a 45-minute case study. However, the underlying flow is the same (see the method in action in the video below)

Let's zoom in to see how our method actually works in more detail:

4.1. Identify the problem

Identifying the problem means properly understanding the prompt/question you are given, so you get to the actual point of the case.

This might sound simple, but cases are often very tricky, and many candidates irretrievably mess things up within the first few minutes of starting. Often, they won’t notice this has happened until they are getting to the end of their analysis. Then, they suddenly realise that they have misunderstood the case prompt - and have effectively been answering the wrong question all along!

With no time to go back and start again, there is nothing to do. Even if there were time, making such a silly mistake early on will make a terrible impression on their interviewer, who might well have written them off already. The interview is scuppered and all the candidate’s preparation has been for nothing.

This error is so galling as it is so readily avoidable.

Our method prevents this problem by placing huge emphasis on a full understanding of the case prompt. This lays the foundations for success as, once we have identified the fundamental, underlying problem our client is facing, we focus our whole analysis around finding solutions to this specific issue.

Now, some case interview prompts are easy to digest. For example, “Our client, a supermarket, has seen a decline in profits. How can we bring them up?”. However, many of the prompts given in interviews for top firms are much more difficult and might refer to unfamiliar business areas or industries. For example, “How much would you pay for a banking license in Ghana?” or “What would be your key areas of concern be when setting up an NGO?”

Don’t worry if you have no idea how you might go about tackling some of these prompts!

In our article on identifying the problem and in our full lesson on the subject in our MCC Academy course, we teach a systematic, four step approach to identifying the problem , as well as running through common errors to ensure you start off on the right foot every time!

This is summarised here:

Following this method lets you excel where your competitors mess up and get off to a great start in impressing your interviewer!

4.2. Build your problem driven structure

After you have properly understood the problem, the next step is to successfully crack a case is to draw up a bespoke structure that captures all the unique features of the case.

This is what will guide your analysis through the rest of the case study and is precisely the same method used by real consultants working on real engagements.

Of course, it might be easier here to simply roll out one an old-fashioned framework, and a lot of candidates will do so. This is likely to be faster at this stage and requires a lot less thought than our problem-driven structure approach.

However, whilst our problem driven structure approach requires more work from you, our method has the advantage of actually working in the kind of complex case studies where generic frameworks fail - that is exactly the kind of cases you can expect at an MBB interview .

Since we effectively start from first principles every time, we can tackle any case with the same overarching method. Simple or complex, every case is the same to you and you don’t have to gamble a job on whether a framework will actually work

4.2.1 Issue trees

Issue trees break down the overall problem into a set of smaller problems that you can then solve individually. Representing this on a diagram also makes it easy for both you and your interviewer to keep track of your analysis.

To see how this is done, let’s look at the issue tree below breaking down the revenues of an airline:

These revenues can be segmented as the number of customers multiplied by the average ticket price. The number of customers can be further broken down into a number of flights multiplied by the number of seats, times average occupancy rate. The node corresponding to the average ticket price can then be segmented further.

4.2.2 Hypothesis trees

Hypothesis trees are similar, the only difference being that rather than just trying to break up the issue into smaller issues you are assuming that the problem can be solved and you are formulating solutions.

In the example above, you would assume revenues can be increased by either increasing the average ticket price or the number of customers . You can then hypothesize that you can increase the average occupancy rate in three ways: align the schedule of short and long haul flights, run a promotion to boost occupancy in off-peak times, or offer early bird discounts.

4.2.3 Other structures:structured lists

Structured lists are simply subcategories of a problem into which you can fit similar elements. This McKinsey case answer starts off by identifying several buckets such as retailer response, competitor response, current capabilities and brand image and then proceeds to consider what could fit into these categories.

Buckets can be a good way to start the structure of a complex case but when using them it can be very difficult to be MECE and consistent, so you should always aim to then re-organize them into either an issue or a hypothesis tree.

It is worth noting that the same problem can be structured in multiple valid ways by choosing different means to segment the key issues. Ultimately all these lists are methods to set out a logical hierachy among elements.

4.2.4 Structures in practice

That said, not all valid structures are equally useful in solving the underlying problem. A good structure fulfils several requirements - including MECE-ness , level consistency, materiality, simplicity, and actionability. It’s important to put in the time to master segmentation, so you can choose a scheme isn’t only valid, but actually useful in addressing the problem.

After taking the effort to identify the problem properly, an advantage of our method is that it will help ensure you stay focused on that same fundamental problem throughout. This might not sound like much, but many candidates end up getting lost in their own analysis, veering off on huge tangents and returning with an answer to a question they weren’t asked.

Another frequent issue - particularly with certain frameworks - is that candidates finish their analysis and, even if they have successfully stuck to the initial question, they have not actually reached a definite solution. Instead, they might simply have generated a laundry list of pros and cons, with no clear single recommendation for action.

Clients employ consultants for actionable answers, and this is what is expected in the case interview. The problem driven structure excels in ensuring that everything you do is clearly related back to the key question in a way that will generate a definitive answer. Thus, the problem driven structure builds in the hypothesis driven approach so characteristic of real consulting practice.

You can learn how to set out your own problem driven structures in our article here and in our full lesson in the MCC Academy course.

4.2. Lead the analysis

A problem driven structure might ensure we reach a proper solution eventually, but how do we actually get there?

We call this step " leading the analysis ", and it is the process whereby you systematically navigate through your structure, identifying the key factors driving the issue you are addressing.

Generally, this will mean continuing to grow your tree diagram, further segmenting what you identify as the most salient end nodes and thus drilling down into the most crucial factors causing the client’s central problem.

Once you have gotten right down into the detail of what is actually causing the company’s issues, solutions can then be generated quite straightforwardly.

To see this process in action, we can return to our airline revenue example:

Let’s say we discover the average ticket price to be a key issue in the airline’s problems. Looking closer at the drivers of average ticket price, we find that the problem lies with economy class ticket prices. We can then further segment that price into the base fare and additional items such as food.

Having broken down the issue to such a fine-grained level and considering the 80/20 rule(see below), solutions occur quite naturally. In this case, we can suggest incentivising the crew to increase onboard sales, improving assortment in the plane, or offering discounts for online purchases.

Our article on leading the analysis is a great primer on the subject, with our video lesson in the MCC Academy providing the most comprehensive guide available.

4.4. Provide recommendations

So you have a solution - but you aren’t finished yet!

Now, you need to deliver your solution as a final recommendation.

This should be done as if you are briefing a busy CEO and thus should be a one minute, top-down, concise, structured, clear, and fact-based account of your findings.

The brevity of the final recommendation belies its importance. In real life consulting, the recommendation is what the client has potentially paid millions for - from their point of view, it is the only thing that matters.

In an interview, your performance in this final summing up of your case is going to significantly colour your interviewer’s parting impression of you - and thus your chances of getting hired!

So, how do we do it right?

Barbara Minto's Pyramid Principle elegantly sums up almost everything required for a perfect recommendation. The answer comes first , as this is what is most important. This is then supported by a few key arguments , which are in turn buttressed by supporting facts .

Across the whole recommendation, the goal isn’t to just summarise what you have done. Instead, you are aiming to synthesize your findings to extract the key "so what?" insight that is useful to the client going forward.

All this might seem like common sense, but it is actually the opposite of how we relay results in academia and other fields. There, we typically move from data, through arguments and eventually to conclusions. As such, making good recommendations is a skill that takes practice to master.

We can see the Pyramid Principle illustrated in the diagram below:

To supplement the basic Pyramid Principle scheme, we suggest candidates add a few brief remarks on potential risks and suggested next steps . This helps demonstrate the ability for critical self-reflection and lets your interviewer see you going the extra mile.

The combination of logical rigour and communication skills that is so definitive of consulting is particularly on display in the final recommendation.

Despite it only lasting 60 seconds, you will need to leverage a full set of key consulting skills to deliver a really excellent recommendation and leave your interviewer with a good final impression of your case solving abilities.

Our specific article on final recommendations and the specific video lesson on the same topic within our MCC Academy are great, comprehensive resources. Beyond those, our lesson on consulting thinking and our articles on MECE and the Pyramid Principle are also very useful.

4.5. What if I get stuck?

Naturally with case interviews being difficult problems there may be times where you’re unsure what to do or which direction to take. The most common scenario is that you will get stuck midway through the case and there are essentially two things that you should do:

• 1. Go back to your structure
• 2. Ask the interviewer for clarification

Your structure should always be your best friend - after all, this is why you put so much thought and effort into it: if it’s MECE it will point you in the right direction. This may seem abstract but let’s take the very simple example of a profitability issue: if you’ve started your analysis by segmenting profit into revenue minus costs and you’ve seen that the cost side of the analysis is leading you nowhere, you can be certain that the declining profit is due to a decline in revenue.

Similarly, when you’re stuck on the quantitative section, make sure that your framework for calculations is set up correctly (you can confirm this with the interviewer) and see what it is you’re trying to solve for: for example if you’re trying to find what price the client should sell their new t-shirt in order to break even on their investment, you should realize that what you’re trying to find is the break even point, so you can start by calculating either the costs or the revenues. You have all the data for the costs side and you know they’re trying to sell 10.000 pairs so you can simply set up the equation with x being the price.

As we’ve emphasised on several occasions, your consulting interview will be a dialogue. As such, if you don’t know what to do next or don’t understand something, make sure to ask the interviewer (and as a general rule always follow their prompts as they are trying to help, not trick you). This is especially true for the quantitative questions, where you should really understand what data you’re looking at before you jump into any calculations. Ideally you should ask your questions before you take time to formulate your approach but don’t be afraid to ask for further clarification if you really can’t make sense of what’s going on. It’s always good to walk your interviewer through your approach before you start doing the calculations and it’s no mistake to make sure that you both have the same understanding of the data. For example when confronted with the chart below, you might ask what GW (in this case gigawatt) means from the get-go and ask to confirm the different metrics (i.e. whether 1 GW = 1000 megawatts). You will never be penalised for asking a question like that.

5. What to remember in case interviews

If you’re new to case cracking you might feel a bit hopeless when you see a difficult case question, not having any idea where to start.

In fact though, cracking cases is much like playing chess. The rules you need to know to get started are actually pretty simple. What will make you really proficient is time and practice.

In this section, we’ll run through a high level overview of everything you need to know, linking to more detailed resources at every step.

5.1. An overall clear structure

You will probably hear this more than you care for but it is the most important thing to keep in mind as you start solving cases, as not only it is a key evaluation criterion but the greatest tool you will have at your disposal. The ability to build a clear structure in all aspects of the case will be the difference between breezing through a complicated case and struggling at its every step. Let’s look a bit closer at the key areas where you should be structured!

5.1.1 Structured notes

Every case interview starts with a prompt, usually verbal, and as such you will have to take some notes. And here is where your foray into structure begins, as the notes you take should be clear, concise and structured in a way that will allow you to repeat the case back to the interviewer without writing down any unnecessary information.

This may sound very basic but you should absolutely not be dismissive about it: taking clear and organized notes will allow you to navigate a case just like you would a powerpoint! While you should obviously adopt a system that you are comfortable with, what we found helps is to have separate sections for:

• The case brief
• Follow-up questions and answers
• Numerical data
• Case structure (the most crucial part when solving the case)
• Any scrap work during the case (usually calculations)

When solving the case - or, as we call it here, in the Lead the analysis step, it is highly recommended to keep on feeding and integrating your structure, so that you never get lost. Maintaining a clear high level view is one of the most critical skills in consulting: by constantly keeping track of where you are following your structure, you’ll never lose your focus on the end goal.

In the case of an interviewer-led case, you can also have separate sheets for each question (e.g. Question 1. What factors can we look at that drive profitability?). If you develop a system like this you’ll know exactly where to look for each point of data rather than rummage around in untidy notes. There are a couple more sections that you may have, depending on preference - we’ll get to these in the next sections.

5.1.2 Structured communication

There will be three main types of communication in cases:

• 1. Asking and answering questions
• 2. Walking the interviewer through your structure (either the case or calculation framework - we’ll get to that in a bit!)
• 3. Delivering your recommendation

Asking and answering questions will be the most common of these and the key thing to do before you speak is ask for some time to collect your thoughts and get organised. What you want to avoid is a ‘laundry list’ of questions or anything that sounds too much like a stream of consciousness.

Different systems work for different candidates but a sure-fire way of being organised is numbering your questions and answers. So rather than saying something like ‘I would like to ask about the business model, operational capacity and customer personas’ it’s much better to break it down and say something along the lines of ‘I’ve got three key questions. Firstly I would like to inquire into the business model of our client. Secondly I would like to ask about their operational capacity. Thirdly I would like to know more about the different customer personas they are serving’.

A similar principle should be applied when walking the interview through your structure, and this is especially true of online interviews (more and more frequent now) when the interviewer can’t see your notes. Even if you have your branches or buckets clearly defined, you should still use a numbering system to make it obvious to the interviewer. So, for example, when asked to identify whether a company should make an acquisition, you might say ‘I would like to examine the following key areas. Firstly the financial aspects of this issue, secondly the synergies and thirdly the client’s expertise’

The recommendation should be delivered top-down (see section 4.4 for specifics) and should employ the same numbering principle. To do so in a speedy manner, you should circle or mark the key facts that you encounter throughout the case so you can easily pull them out at the end.

5.1.3 Structured framework

It’s very important that you have a systematic approach - or framework - for every case. Let’s get one thing straight: there is a difference between having a problem-solving framework for your case and trying to force a case into a predetermined framework. Doing the former is an absolute must , whilst doing the latter will most likely have you unceremoniously dismissed.

We have seen there are several ways of building a framework, from identifying several categories of issues (or ‘buckets’) to building an issue or hypothesis tree (which is the most efficient type of framework). For the purpose of organization, we recommend having a separate sheet for the framework of the case, or, if it’s too much to manage, you can have it on the same sheet as the initial case prompt. That way you’ll have all the details as well as your proposed solution in one place.

5.1.4 Structured calculations

Whether it’s interviewer or candidate-led, at some point in the case you will get a bunch of numerical data and you will have to perform some calculations (for the specifics of the math you’ll need on consulting interviews, have a look at our Consulting Math Guide ). Here’s where we urge you to take your time and not dive straight into calculating! And here’s why: while your numerical agility is sure to impress interviewers, what they’re actually looking for is your logic and the calculations you need to perform in order to solve the problem . So it’s ok if you make a small mistake, as long as you’re solving for the right thing.

As such, make it easy for them - and yourself. Before you start, write down in steps the calculations you need to perform. Here’s an example: let’s say you need to find out by how much profits will change if variable costs are reduced by 10%. Your approach should look something like:

• 1. Calculate current profits: Profits = Revenues - (Variable costs + Fixed costs)
• 2. Calculate the reduction in variable costs: Variable costs x 0.9
• 3. Calculate new profits: New profits = Revenues - (New variable costs + Fixed costs)

Of course, there may be more efficient ways to do that calculation, but what’s important - much like in the framework section - is to show your interviewer that you have a plan, in the form of a structured approach. You can write your plan on the sheet containing the data, then perform the calculations on a scrap sheet and fill in the results afterward.

5.2. Common business knowledge and formulas

Although some consulting firms claim they don’t evaluate candidates based on their business knowledge, familiarity with basic business concepts and formulae is very useful in terms of understanding the case studies you are given in the first instance and drawing inspiration for structuring and brainstorming.

If you are coming from a business undergrad, an MBA or are an experienced hire, you might well have this covered already. For those coming from a different background, it may be useful to cover some.

Luckily, you don’t need a degree-level understanding of business to crack interview cases , and a lot of the information you will pick up by osmosis as you read through articles like this and go through cases.

However, some things you will just need to sit down and learn. We cover everything you need to know in some detail in our Case Academy Course course. However, some examples here of things you need to learn are:

• Basic accounting (particularly how to understand all the elements of a balance sheet)
• Basic economics
• Basic marketing
• Basic strategy

Below we include a few elementary concepts and formulae so you can hit the ground running in solving cases. We should note that you should not memorise these and indeed a good portion of them can be worked out logically, but you should have at least some idea of what to expect as this will make you faster and will free up much of your mental computing power. In what follows we’ll tackle concepts that you will encounter in the private business sector as well as some situations that come up in cases that feature clients from the NGO or governmental sector.

5.2.1 Business sector concepts

These concepts are the bread and butter of almost any business case so you need to make sure you have them down. Naturally, there will be specificities and differences between cases but for the most part here is a breakdown of each of them.

5.2.1.1. Revenue

The revenue is the money that the company brings in and is usually equal to the number of products they sell multiplied to the price per item and can be expressed with the following equation:

Revenue = Volume x Price

Companies may have various sources of revenue or indeed multiple types of products, all priced differently which is something you will need to account for. Let’s consider some situations. A clothing company such as Nike will derive most of their revenue from the number of products they sell times the average price per item. Conversely, for a retail bank revenue is measured as the volume of loans multiplied by the interest rate at which the loans are given out. As we’ll see below, we might consider primary revenues and ancillary revenues: in the case of a football club, we might calculate primary revenues by multiplying the number of tickets sold by the average ticket price, and ancillary revenues those coming from sales of merchandise (similarly, let’s say average t-shirt price times the number of t-shirts sold), tv rights and sponsorships.

These are but a few examples and another reminder that you should always aim to ask questions and understand the precise revenue structure of the companies you encounter in cases.

5.2.1.2. Costs

The costs are the expenses that a company incurs during its operations. Generally, they can be broken down into fixed and variable costs :

Costs = Fixed Costs + Variable Costs

As their name implies, fixed costs do not change based on the number of units produced or sold. For example, if you produce shoes and are renting the space for your factory, you will have to pay the rent regardless of whether you produce one pair or 100. On the other hand, variable costs depend on the level of activity, so in our shoe factory example they would be equivalent to the materials used to produce each pair of shoes and would increase the more we produce.

These concepts are of course guidelines used in order to simplify the analysis in cases, and you should be aware that in reality often the situation can be more complicated. Costs can also be quasi-fixed, in that they increase marginally with volume. Take the example of a restaurant which has a regular staff, incurring a fixed cost but during very busy hours or periods they also employ some part-time workers. This cost is not exactly variable (as it doesn’t increase with the quantity of food produced) but also not entirely fixed, as the number of extra hands will depend on how busy the restaurant is. Fixed costs can also be non-linear in nature. Let’s consider the rent in the same restaurant: we would normally pay a fixed amount every month, but if the restaurant becomes very popular we might need to rent out some extra space so the cost will increase.

5.2.1.3. Profit and profit margin

The profit is the amount of money a company is left with after it has paid all of its expenses and can be expressed as follows:

Profit = Revenue - Costs

It’s very likely that you will encounter a profitability issue in one of your cases, namely you will be asked to increase a company’s profit. There are two main ways of doing this: increasing revenues and reducing costs , so these will be the two main areas you will have to investigate. This may seem simple but what you will really need to understand in a case are the key drivers of a business (and this should be done through clarifying questions to the interviewer - just as a real consultant would question their client).

For example, if your client is an airline you can assume that the main source of revenue is sales of tickets, but you should inquire how many types of ticket the specific airline sells. You may naturally consider economy and business class tickets, but you may find out that there is a more premium option - such as first class - and several in-between options. Similarly to our football club example, there may be ancillary revenues from selling of food and beverage as well as advertising certain products or services on flights.

You may also come across the profit margin in cases. This is simply the percentage of profit compared to the revenue and can be expressed as follows:

Profit margin = Profit/Revenue x 100

5.2.1.4. Break-even point

An ancillary concept to profit, the break-even point is the moment where revenues equal costs making the profit zero and can be expressed as the following equation:

Revenues = Costs (Fixed costs + Variable costs)

This formula will be useful when you are asked questions such as ‘What is the minimum price I should sell product X?’ or ‘What quantity do I need to sell in order to recoup my investment?’. Let’s say an owner of a sandwich store asks us to figure out how many salami and cheese salami sandwiches she needs to sell in order to break even. She’s spending $4 on salami and $2 for cheese and lettuce per sandwich, and believes she can sell the sandwiches at around $7. The cost of utilities and personnel is around $5000 per month. We could lay this all out in the break-even equation:

7 x Q ( quantity ) = (4+2) x Q + 5000 ( variable + fixed costs )

In a different scenario, we may be asked to calculate the break-even price . Let’s consider our sandwich example and say our owner knows she has enough ingredients for about 5000 sandwiches per month but is not sure how much to sell them for. In that case, if we know our break-even equation, we can simply make the following changes:

P ( price ) x 5000 = (4+2) x 5000 + 5000

By solving the equation we get to the price of $7 per sandwich.

5.2.1.5. Market share and market size

We can also consider the market closely with profit, as in fact the company’s performance in the market is what drives profits. The market size is the total number of potential customers for a certain business or product, whereas the market share is the percentage of that market that your business controls (or could control, depending on the case).

There is a good chance you will have to estimate the market size in one of your case interviews and we get into more details on how to do that below. You may be asked to estimate this in either number of potential customers or total value . The latter simply refers to the number of customers multiplied by the average value of the product or service.

To calculate the market share you will have to divide the company’s share by the total market size and multiply by 100:

Note, though, that learning the very basics of business is the beginning rather than the end of your journey. Once you are able to “speak business” at a rudimentary level, you should try to “become fluent” and immerse yourself in reading/viewing/listening to as wide a variety of business material as possible, getting a feel for all kinds of companies and industries - and especially the kinds of problems that can come up in each context and how they are solved. The material put out by the consulting firms themselves is a great place to start, but you should also follow the business news and find out about different companies and sectors as much as possible between now and interviews. Remember, if you’re going to be a consultant, this should be fun rather than a chore!

5.3 Public sector and NGO concepts

As we mentioned, there will be some cases (see section 6.6 for a more detailed example) where the key performance indicators (or KPIs in short) will not be connected to profit. The most common ones will involve the government of a country or an NGO, but they can be way more diverse and require more thought and application of first principles. We have laid out a couple of the key concepts or KPIs that come up below

5.3.1 Quantifiability

In many such scenarios you will be asked to make an important strategic decision of some kind or to optimise a process. Of course these are not restricted to non-private sector cases but this is where they really come into their own as there can be great variation in the type of decision and the types of field.

While there may be no familiar business concepts to anchor yourself onto, a concept that is essential is quantifiability . This means, however qualitative the decision might seem, consultants rely on data so you should always aim to have aspects of a decision that can be quantified, even if the data doesn’t present itself in a straightforward manner.

Let’s take a practical example. Your younger sibling asks you to help them decide which university they should choose if they want to study engineering. One way to structure your approach would be to segment the problem into factors affecting your sibling’s experience at university and experience post-university. Within the ‘at uni’ category you might think about the following:

• Financials : How much are tuition costs and accommodation costs?
• Quality of teaching and research : How are possible universities ranked in the QS guide based on teaching and research?
• Quality of resources : How well stocked is their library, are the labs well equipped etc.?
• Subject ranking : How is engineering at different unis ranked?
• Life on campus and the city : What are the living costs in the city where the university is based? What are the extracurricular opportunities and would your sibling like to live in that specific city based on them?

Within the ‘out of uni’ category you might think about:

• Exit options : What are the fields in which your sibling could be employed and how long does it take the average student of that university to find a job?
• Alumni network : What percentage of alumni are employed by major companies?
• Signal : What percentage of applicants from the university get an interview in major engineering companies and related technical fields?

You will perhaps notice that all the buckets discussed pose quantifiable questions meant to provide us with data necessary to make a decision. It’s no point to ask ‘Which university has the nicest teaching staff?’ as that can be a very subjective metric.

5.3.1 Impact

Another key concept to consider when dealing with sectors other than the private one is how impactful a decision or a line of inquiry is on the overarching issue , or whether all our branches in our issue tree have a similar impact. This can often come in the form of impact on lives, such as in McKinsey’s conservation case discussed below, namely how many species can we save with our choice of habitat.

5.4 Common consulting concepts

Consultants use basic business concepts on an every day basis, as they help them articulate their frameworks to problems. However, they also use some consulting specific tools to quality check their analysis and perform in the most efficient way possible. These principles can be applied to all aspects of a consultant’s work, but for brevity we can say they mostly impact a consultant’s systematic approach and communication - two very important things that are also tested in case interviews. Therefore, it’s imperative that you not only get to know them, but learn how and when to use them as they are at the very core of good casing. They are MECE-ness, the Pareto Principle and the Pyramid principle and are explained briefly below - you should, however, go on to study them in-depth in their respective articles.

Perhaps the central pillar of all consulting work and an invaluable tool to solve cases, MECE stands for Mutually Exclusive and Collectively Exhaustive . It can refer to any and every aspect in a case but is most often used when talking about structure. We have a detailed article explaining the concept here , but the short version is that MECE-ness ensures that there is no overlap between elements of a structure (i.e. the Mutually Exclusive component) and that it covers all the drivers or areas of a problem (Collectively Exhaustive). It is a concept that can be applied to any segmentation when dividing a set into subsets that include it wholly but do not overlap.

Let’s take a simple example and then a case framework example. In simple terms, when we are asked to break down the set ‘cars’ into subsets, dividing cars into ‘red cars’ and ‘sports cars’ is neither mutually exclusive (as there are indeed red sports cars) nor exhaustive of the whole set (i.e. there are also yellow non-sports cars that are not covered by this segmentation). A MECE way to segment would be ‘cars produced before 2000’ and ‘cars produced after 2000’ as this segmentation allows for no overlap and covers all the cars in existence.

Dividing cars can be simple, but how can we ensure MECEness in a case-interview a.k.a. a business situation. While the same principles apply, a good tip to ensure that your structure is MECE is to think about all the stakeholders - i.e. those whom a specific venture involves.

Let’s consider that our client is a soda manufacturer who wants to move from a business-to-business strategy, i.e. selling to large chains of stores and supermarkets, to a business-to-consumer strategy where it sells directly to consumers. In doing so they would like to retrain part of their account managers as direct salespeople and need to know what factors to consider.

A stakeholder-driven approach would be to consider the workforce and customers and move further down the issue tree, thinking about individual issues that might affect them. In the case of the workforce, we might consider how the shift would affect their workload and whether it takes their skillset into account. As for the customers, we might wonder whether existing customers would be satisfied with this move: will the remaining B2B account managers be able to provide for the needs of all their clients and will the fact that the company is selling directly to consumers now not cannibalise their businesses? We see how by taking a stakeholder-centred approach we can ensure that every single perspective and potential issue arising from it is fully covered.

5.4.2 The Pareto Principle

Also known as the 80/20 rule, this principle is important when gauging the impact of a decision or a factor in your analysis. It simply states that in business (but not only) 80% of outcomes come from 20% of causes. What this means is you can make a few significant changes that will impact most of your business organisation, sales model, cost structure etc.

Let’s have a look at 3 quick examples to illustrate this:

• 80% of all accidents are caused by 20% of drivers
• 20% of a company’s products account for 80% of the sales
• 80% of all results in a company are driven by 20% of its employees

The 80/20 rule will be a very good guide line in real engagements as well as case interviews, as it will essentially point to the easiest and most straightforward way of doing things. Let’s say one of the questions in a case is asking you to come up with an approach to understand the appeal of a new beard trimmer. Obviously you can’t interview the whole male population so you might think about setting up a webpage and asking people to comment their thoughts. But what you would get would be a laundry list of difficult to sift through data.

Using an 80/20 approach you would segment the population based on critical factors (age groups, grooming habits etc.) and then approach a significant sample size of each (e.g. 20), analysing the data and reaching a conclusion.

5.4.3 The Pyramid Principle

This principle refers to organising your communication in a top-down , efficient manner. While this is generally applicable, the pyramid principle will most often be employed when delivering the final recommendation to your client. This means - as is implicit in the name - that you would organise your recommendation (and communication in general) as a pyramid, stating the conclusion or most important element at the top then go down the pyramid listing 3 supporting arguments and then further (ideally also 3) supporting arguments for those supporting arguments.

Let’s look at this in practice: your client is a German air-conditioning unit manufacturer who was looking to expand into the French market. However, after your analysis you’ve determined that the market share they were looking to capture would not be feasible. A final recommendation using the Pyramid Principle would sound something like this: ‘I recommend that we do not enter the German market for the following three reasons. Firstly, the market is too small for our ambitions of $50 million. Secondly the market is heavily concentrated, being controlled by three major players and our 5 year goal would amount to controlling 25% of the market, a share larger than that of any of the players. Thirdly, the alternative of going into the corporate market would not be feasible, as it has high barriers to entry.Then, if needed, we could delve deeper into each of our categories

6. Case examples or building blocks?

As we mentioned before, in your preparation you will undoubtedly find preparation resources that claim that there are several standard types of cases and that there is a general framework that can be applied to each type of case. While there are indeed cases that are straightforward at least in appearance and seemingly invite the application of such frameworks, the reality is never that simple and cases often involve multiple or more complicated components that cannot be fitted into a simple framework.

At MCC we don’t want you to get into the habit of trying to identify which case type you’re dealing with and pull out a framework, but we do recognize that there are recurring elements in frameworks that are useful - such as the profitability of a venture (with its revenues and costs), the valuation of a business, estimating and segmenting a market and pricing a product.

We call these building blocks because they can be used to build case frameworks but are not a framework in and of themselves, and they can be shuffled around and rearranged in any way necessary to be tailored to our case. Hence, our approach is not to make you think in terms of case types but work from first principles and use these building blocks to build your own framework. Let’s take two case prompts to illustrate our point.

The first is from the Bain website, where the candidate is asked whether they think it’s a good idea for their friend to open a coffee shop in Cambridge UK (see the case here ). The answer framework provided here is a very straightforward profitability analysis framework, examining the potential revenues and potential costs of the venture:

While this is a good point to start (especially taken together with the clarifying questions), we will notice that this approach will need more tailoring to the case - for example the quantity of coffee will be determined by the market for coffee drinkers in Cambridge, which we have to determine based on preference. We are in England so a lot of people will be drinking tea but we are in a university town so perhaps more people than average are drinking coffee as it provides a better boost when studying. All these are some much needed case-tailored hypotheses that we can make based on the initial approach.

Just by looking at this case we might be tempted to say that we can just take a profitability case and apply it without any issues. However, this generic framework is just a starting point and in reality we would need to tailor it much further in the way we had started to do in order to get to a satisfactory answer. For example, the framework itself doesn’t cover aspects such as the customer’s expertise: does the friend have any knowledge of the coffee business, such as where to source coffee and how to prepare it? Also, we could argue there may be some legal factors to consider here, such as any approvals that they might need from the city council to run a coffee shop on site, or some specific trade licences that are not really covered in the basic profitability framework.

Let’s take a different case , however, from the McKinsey website. In this scenario, the candidate is being asked to identify some factors in order to choose where to focus the client’s conservation efforts. Immediately we can realise that this case doesn’t lend itself to any pre-packaged framework and we will need to come up with something from scratch - and take a look at McKinsey’s answer of the areas to focus on:

We notice immediately that this framework is 100% tailored to the case - of course there are elements which we encounter in other cases, such as costs and risks but again these are applied in an organic way. It’s pretty clear that while no standard framework would work in this case, the aforementioned concepts - costs and risks - and the way to approach them (a.k.a building blocks ) are fundamentally similar throughout cases (with the obvious specificities of each case).

In what follows, we’ll give a brief description of each building block starting from the Bain example discussed previously, in order to give you a general idea of what they are and their adaptability, but you should make sure to follow the link to the in-depth articles to learn all their ins and outs.

6.1 Estimates and segmentation

This building block will come into play mostly when you’re thinking about the market for a certain product (but make sure to read the full article for more details). Let’s take our Bain Cambridge coffee example. As we mentioned under the quantity bucket we need to understand what the market size for coffee in Cambridge would be - so we can make an estimation based on segmentation .

The key to a good estimation is the ability to logically break down the problem into more manageable pieces. This will generally mean segmenting a wider population to find a particular target group. We can start off with the population of Cambridge - which we estimate at 100.000. In reality the population is closer to 150.000 but that doesn’t matter - the estimation has to be reasonable and not accurate , so unless the interviewer gives you a reason to reconsider you can follow your instinct. We can divide that into people who do and don’t drink coffee. Given our arguments before, we can conclude that 80% of those, so 80.000 drink coffee. Then we can further segment into those who drink regularly - let’s say every day - and those who drink occasionally - let’s say once a week. Based on the assumptions before about the student population needing coffee to function, and with Cambridge having a high student population, we can assume that 80% of those drinking coffee are regular drinkers, so that would be 64.000 regular drinkers and 16.000 occasional drinkers. We can then decide whom we want to target what our strategy needs to be:

This type of estimation and segmentation can be applied to any case specifics - hence why it is a building block.

6.2 Profitability

We had several looks at this building block so far (see an in-depth look here ) as it will show up in most scenarios, since profit is a key element in any company’s strategy. As we have seen, the starting point to this analysis is to consider both the costs and revenues of a company, and try to determine whether revenues need to be improved or whether costs need to be lowered. In the coffee example, the revenues are dictated by the average price per coffe x the number of coffees sold , whereas costs can be split into fixed and variable .

Some examples of fixed costs would be the rent for the stores and the cost of the personnel and utilities, while the most obvious variable costs would be the coffee beans used and the takeaway containers (when needed). We may further split revenues in this case into Main revenues - i.e. the sales of coffee - and Ancillary revenues , which can be divided into Sales of food products (sales of pastries, sandwiches etc., each with the same price x quantity schema) and Revenues from events - i.e renting out the coffee shop to events and catering for the events themselves. Bear in mind that revenues will be heavily influenced by the penetration rate , i.e. the share of the market which we can capture.

6.3 Pricing

Helping a company determine how much they should charge for their goods or services is another theme that comes up frequently in cases. While it may seem less complicated than the other building blocks, we assure you it’s not - you will have to understand and consider several factors, such as the costs a company is incurring, their general strategic positioning, availability, market trends as well as the customers’ willingness to pay (or WTP in short) - so make sure to check out our in-depth guide here .

In our example, we may determine that the cost per cup (coffee beans, staff, rent) is £1. We want to be student friendly so we should consider how much students would want to pay for a coffee as well as how much are competitors are charging. Based on those factors, it would be reasonable to charge on average £2 per cup of coffee. It’s true that our competitors are charging £3 but they are targeting mostly the adult market, whose willingness to pay is higher, so their pricing model takes that into account as well as the lower volume of customers in that demographic.

6.4. Valuation

A variant of the pricing building block, a valuation problem generally asks the candidate to determine how much a client should pay for a specific company (the target of an acquisition) as well as what other factors to consider. The two most important factors (but not the only ones - for a comprehensive review see our Valuation article ) to consider are the net present value (in consulting interviews usually in perpetuity) and the synergies .

In short, the net present value of a company is how much profit it currently brings in, divided by how much that cash flow will depreciate in the future and can be represented with the equation below:

The synergies refer to what could be achieved should the companies operate as one, and can be divided into cost and revenue synergies .

Let’s expand our coffee example a bit to understand these. Imagine that our friend manages to open a chain of coffee shops in Cambridge and in the future considers acquiring a chain of take-out restaurants. The most straightforward example of revenue synergies would be cross-selling, in this case selling coffee in the restaurants as well as in the dedicated stores, and thus getting an immediate boost in market share by using the existing customers of the restaurant chain. A cost synergy would be merging the delivery services of the two businesses to deliver both food and coffee, thus avoiding redundancies and reducing costs associated with twice the number of drivers and vehicles.

6.5. Competitive interaction

This component of cases deals with situations where the market in which a company is operating changes and the company must decide what to do. These changes often have to do with a new player entering the market (again for more details make sure to dive into the Competitive Interaction article ).

Let’s assume that our Cambridge coffee shop has now become a chain and has flagged up to other competitors that Cambridge is a blooming market for coffee. As such, Starbucks has decided to open a few stores in Cambridge themselves, to test this market. The question which might be posed to a candidate is what should our coffee chain do. One way (and a MECE one) to approach the problem is to decide between doing something and doing nothing . We might consider merging with another coffee chain and pooling our resources or playing to our strengths and repositioning ourselves as ‘your student-friendly, shop around the corner’. Just as easily we may just wait the situation out and see whether indeed Starbucks is cutting into our market share - after all, the advantages of our product and services might speak for themselves and Starbucks might end up tanking. Both of these are viable options if argued right and depending on the further specifics of the case.

6.6. Special cases

Most cases deal with private sectors, where the overarching objective entails profit in some form. However, as hinted before, there are cases which deal with other sectors where there are other KPIs in place . The former will usually contain one or several of these building blocks whereas the latter will very likely have neither. This latter category is arguably the one that will stretch your analytical and organisational skills to the limit, since there will be very little familiarity that you can fall back on (McKinsey famously employs such cases in their interview process).

So how do we tackle the structure for such cases? The short answer would be starting from first principles and using the problem driven structure outlined above, but let’s look at a quick example in the form of a McKinsey case :

The first question addressed to the candidate is the following:

This is in fact asking us to build a structure for the case. So what should we have in mind here? Most importantly, we should start with a structure that is MECE and we should remember to do that by considering all the stakeholders . They are on the one hand the government and affiliated institutions and on the other the population. We might then consider which issues might arise for each shareholder and what the benefits for them would be, as well as the risks. This approach is illustrated in the answer McKinsey provides as well:

More than anything, this type of case shows us how important it is to practise and build different types of structures, and think about MECE ways of segmenting the problem.

7. How Do I prepare for case interviews

In consulting fashion, the overall preparation can be structured into theoretical preparation and practical preparation , with each category then being subdivided into individual prep and prep with a partner .

As a general rule, the level and intensity of the preparation will differ based on your background - naturally if you have a business background (and have been part of a consulting club or something similar) your preparation will be less intensive than if you’re starting from scratch. The way we suggest you go about it is to start with theoretical preparation , which means learning about case interviews, business and basic consulting concepts (you can do this using free resources - such as the ones we provide - or if you want a more through preparation you can consider joining our Case Academy as well).

You can then move on to the practical preparation which should start with doing solo cases and focusing on areas of improvement, and then move on to preparation with a partner , which should be another candidate or - ideally - an ex-consultant.

Let’s go into more details with respect to each type of preparation.

7.1. Solo practice

The two most important areas of focus in sole preparation are:

• Mental math

As we mentioned briefly, the best use of your time is to focus on solving cases. You can start with cases listed on MBB sites since they are clearly stated and have worked solutions as well (e.g. Bain is a good place to start) and then move to more complex cases (our Case Library also offers a range of cases of different complexities). To build your confidence, start out on easier case questions, work through with the solutions, and don't worry about time. As you get better, you can move on to more difficult cases and try to get through them more quickly. You should practice around eight case studies on your own to build your confidence.

Another important area of practice is your mental mathematics as this skill will considerably increase your confidence and is neglected by many applicants - much to their immediate regret in the case interview. Find our mental math tool here or in our course, and practice at least ten minutes per day, from day one until the day before the interview.

7.2. Preparation with a partner

There are aspects of an interview - such as asking clarifying questions - which you cannot do alone and this is why, after you feel comfortable, you should move on to practice with another person. There are two options here:

• Practicing with a peer
• Practicing with an ex-consultant

In theory they can be complementary - especially if you’re peer is also preparing for consulting interviews - and each have advantages and disadvantages. A peer is likely to practice with you for free for longer, however you may end up reinforcing some bad habits or unable to get actionable feedback. A consultant will be able to provide you the latter but having their help for the same number of hours as a peer will come at a higher cost. Let’s look at each option in more detail.

7.2.1. Peer preparation

Once you have worked through eight cases solo, you should be ready to simulate the interview more closely and start working with another person.

Here, many candidates turn to peer practice - that is, doing mock case interviews with friends, classmates or others also applying to consulting. If you’re in university, and especially in business school, there will very likely be a consulting club for you to join and do lots of case practice with. If you don’t have anyone to practice, though, or if you just want to get a bit more volume in with others, our free meeting board lets you find fellow applicants from around the world with whom to practice. We recommend practicing around 10 to 15 ‘live’ cases to really get to a point where you feel comfortable.

7.2.2. Preparation with a consultant

You can do a lot practising by yourself and with peers. However, nothing will bring up your skills so quickly and profoundly as working with a real consultant.

Perhaps think about it like boxing. You can practice drills and work on punch bags all you want, but at some point you need to get into the ring and do some actual sparring if you ever want to be ready to fight.

Practicing with an ex consultant is essentialy a simulation of an interview. Of course, it isn’t possible to secure the time of experienced top-tier consultants for free. However, when considering whether you should invest to boost your chances of success, it is worth considering the difference in your salary over even just a few years between getting into a top-tier firm versus a second-tier one. In the light of thousands in increased annual earnings (easily accumulating into millions over multiple years), it becomes clear that getting expert interview help really is one of the best investments you can make in your own future.

Should you decide to make this step, MyConsultingCoach can help, offering bespoke mentoring programmes , where you are paired with a 5+ year experienced, ex-MBB mentor of your choosing, who will then oversee your whole case interview preparation from start to finish - giving you your best possible chance of landing a job!

7.3. Practice for online interviews

Standard preparation for interview case studies will carry directly over to online cases.

However, if you want to do some more specific prep, you can work through cases solo to a timer and using a calculator and/or Excel (online cases generally allow calculators and second computers to help you, whilst these are banned in live case interviews).

Older PST-style questions also make great prep, but a particularly good simulation is the self-assessment tests included in our Case Academy course . These multiple choice business questions conducted with a strict time limit are great preparation for the current crop of online cases.

7.4. Fit interviews

As we’ve noted, even something billed as a case interview is very likely to contain a fit interview as a subset.

We have an article on fit interviews and also include a full set of lessons on how to answer fit questions properly as a subset of our comprehensive Case Academy course .

Here though, the important thing to convey is that you take preparing for fit questions every bit as seriously as you do case prep.

Since they sound the same as you might encounter when interviewing for other industries, the temptation is to regard these as “just normal interview questions”.

However, consulting firms take your answers to these questions a good deal more seriously than elsewhere.

This isn’t just for fluffy “corporate culture” reasons. The long hours and close teamwork, as well as the client-facing nature of management consulting, mean that your personality and ability to get on with others is going to be a big part of making you a tolerable and effective co-worker.

If you know you’ll have to spend 14+ hour working days with someone you hire and that your annual bonus depends on them not alienating clients, you better believe you’ll pay attention to their character in interview.

There are also hard-nosed financial reasons for the likes of McKinsey, Bain and BCG to drill down so hard on your answers.

In particular, top consultancies have huge issues with staff retention. The average management consultant only stays with these firms for around two years before they have moved on to a new industry.

In some cases, consultants bail out because they can’t keep up with the arduous consulting lifestyle of long hours and endless travel. In many instances, though, departing consultants are lured away by exit opportunities - such as the well trodden paths towards internal strategy roles, private equity or becoming a start-up founder.

Indeed, many individuals will intentionally use a two year stint in consulting as something like an MBA they are getting paid for - giving them accelerated exposure to the business world and letting them pivot into something new.

Consulting firms want to get a decent return on investment for training new recruits. Thus, they want hires who not only intend to stick with consulting longer-term, but also have a temperament that makes this feasible and an overall career trajectory where it just makes sense for them to stay put.

This should hammer home the point that, if you want to get an offer, you need to be fully prepared to answer fit questions - and to do so excellently - any time you have a case interview.

8. Interview day - what to expect, with tips

Of course, all this theory is well and good, but a lot of readers might be concerned about what exactly to expect in real life . It’s perfectly reasonable to want to get as clear a picture as possible here - we all want to know what we are going up against when we face a new challenge!

Indeed, it is important to think about your interview in more holistic terms, rather than just focusing on small aspects of analysis. Getting everything exactly correct is less important than the overall approach you take to reasoning and how you communicate - and candidates often lose sight of this fact.

In this section, then, we’ll run through the case interview experience from start to finish, directing you to resources with more details where appropriate. As a supplement to this, the following video from Bain is excellent. It portrays an abridged version of a case interview, but is very useful as a guide to what to expect - not just from Bain, but from McKinsey, BCG and any other high-level consulting firm.

8.1. Getting started

Though you might be shown through to the office by a staff member, usually your interviewer will come and collect you from a waiting area. Either way, when you first encounter them, you should greet your interviewer with a warm smile and a handshake (unless they do not offer their hand). Be confident without verging into arrogance. You will be asked to take a seat in the interviewer’s office, where the interview can then begin.

8.1.1. First impressions

In reality, your assessment begins before you even sit down at your interviewer’s desk. Whether at a conscious level or not, the impression you make within the first few seconds of meeting your interviewer is likely to significantly inform the final hiring decision (again, whether consciously or not).

Your presentation and how you hold yourself and behave are all important . If this seems strange, consider that, if hired, you will be personally responsible for many clients’ impressions of the firm. These things are part of the job! Much of material on the fit interview is useful here, whilst we also cover first impressions and presentation generally in our article on what to wear to interview .

As we have noted above, your interview might start with a fit segment - that is, with the interviewer asking questions about your experiences, your soft skills, and motivation to want to join consulting generally and that firm in particular. In short, the kinds of things a case study can’t tell them about you. We have a fit interview article and course to get you up to speed here.

8.1.2. Down to business

Following an initial conversation, your interviewer will introduce your case study , providing a prompt for the question you have to answer. You will have a pen and paper in front of you and should (neatly) note down the salient pieces of information (keep this up throughout the interview).

It is crucial here that you don’t delve into analysis or calculations straight away . Case prompts can be tricky and easy to misunderstand, especially when you are under pressure. Rather, ask any questions you need to fully understand the case question and then validate that understanding with the interviewer before you kick off any analysis. Better to eliminate mistakes now than experience that sinking feeling of realising you have gotten the whole thing wrong halfway through your case!

This process is covered in our article on identifying the problem and in greater detail in our Case Academy lesson on that subject.

8.1.3. Analysis

Once you understand the problem, you should take a few seconds to set your thoughts in order and draw up an initial structure for how you want to proceed. You might benefit from utilising one or more of our building blocks here to make a strong start. Present this to your interviewer and get their approval before you get into the nuts and bolts of analysis.

We cover the mechanics of how to structure your problem and lead the analysis in our articles here and here and more thoroughly in the MCC Case Academy . What it is important to convey here, though, is that your case interview is supposed to be a conversation rather than a written exam . Your interviewer takes a role closer to a co-worker than an invigilator and you should be conversing with them throughout.

Indeed, how you communicate with your interviewer and explain your rationale is a crucial element of how you will be assessed. Case questions in general, are not posed to see if you can produce the correct answer, but rather to see how you think . Your interviewer wants to see you approach the case in a structured, rational fashion. The only way they are going to know your thought processes, though, is if you tell them!

To demonstrate this point, here is another excellent video from Bain, where candidates are compared.

Note that multiple different answers to each question are considered acceptable and that Bain is primarily concerned with the thought processes of the candidate’s exhibit .

Another reason why communication is absolutely essential to case interview success is the simple reason that you will not have all the facts you need to complete your analysis at the outset. Rather, you will usually have to ask the interviewer for additional data throughout the case to allow you to proceed .

NB: Don't be let down by your math!

Your ability to quickly and accurately interpret these charts and other figures under pressure is one of the skills that is being assessed. You will also need to make any calculations with the same speed and accuracy (without a calculator!). As such, be sure that you are up to speed on your consulting math .

8.1.4. Recommendation

Finally, you will be asked to present a recommendation. This should be delivered in a brief, top-down "elevator pitch" format , as if you are speaking to a time-pressured CEO. Again here, how you communicate will be just as important as the details of what you say, and you should aim to speak clearly and with confidence.

For more detail on how to give the perfect recommendation, take a look at our articles on the Pyramid Principle and providing recommendations , as well the relevant lesson within MCC Academy .

8.1.5. Wrapping up

After your case is complete, there might be a few more fit questions - including a chance for you to ask some questions of the interviewer . This is your opportunity to make a good parting impression.

We deal with the details in our fit interview resources. However, it is always worth bearing in mind just how many candidates your interviewers are going to see giving similar answers to the same questions in the same office. A pretty obvious pre-requisite to being considered for a job is that your interviewer remembers you in the first place. Whilst you shouldn't do something stupid just to be noticed, asking interesting parting questions is a good way to be remembered.

Now, with the interview wrapped up, it’s time to shake hands, thank the interviewer for their time and leave the room .

You might have other interviews or tests that day or you might be heading home. Either way, if know that you did all you could to prepare, you can leave content in the knowledge that you have the best possible chance of receiving an email with a job offer. This is our mission at MCC - to provide all the resources you need to realise your full potential and land your dream consulting job!

8.2. Remote and one-way interview tips

Zoom case interviews and “one-way” automated fit interviews are becoming more common as selection processes are increasingly remote, with these new formats being accompanied by their own unique challenges.

Obviously you won’t have to worry about lobbies and shaking hands for a video interview. However, a lot remains the same. You still need to do the same prep in terms of getting good at case cracking and expressing your fit answers. The specific considerations around remote interviews are, in effect, around making sure you come across as effectively as you would in person.

8.2.1. Connection

It sounds trivial, but a successful video interview of any kind presupposes a functioning computer with a stable and sufficient internet connection.

Absolutely don’t forget to have your laptop plugged in, as your battery will definitely let you down mid-interview. Similarly, make sure any housemates or family know not to use the microwave, vacuum cleaner or anything else that makes wifi cut out (or makes a lot of noise, obviously)

If you have to connect on a platform you don’t use much (for example, if it’s on Teams and you’re used to Zoom), make sure you have the up to date version of the app in advance, rather than having to wait for an obligatory download and end up late to join. Whilst you’re at it, make sure you’re familiar with the controls etc. At the risk of being made fun of, don’t be afraid to have a practice call with a friend.

8.2.2. Dress

You might get guidance on a slightly more relaxed dress code for a Zoom interview. However, if in doubt, dress as you would for the real thing (see our article here ).

Either way, always remember that presentation is part of what you are being assessed on - the firm needs to know you can be presentable for clients. Taking this stuff seriously also shows respect for your interviewer and their time in interviewing you.

8.2.3. Lighting

An aspect of presentation that you have to devote some thought to for a Zoom interview is your lighting.

Hopefully, you long ago nailed a lighting set-up during the Covid lockdowns. However, make sure to check your lighting in advance with your webcam - bearing in mind what time if day your interview actually is. If your interview is late afternoon, don’t just check in the morning. Make sure you aren’t going to be blinded from light coming in a window behind your screen, or that you end up with the weird shadow stripes from blinds all over your face.

Natural light is always best, but if there won’t be much of that during your interview, you’ll likely want to experiment with moving some lamps around.

8.2.4. Clarity

The actual stories you tell in an automated “one-way” fit interview will be the same as for a live equivalent. If anything, things should be easier, as you can rattle off a practised monologue without an interviewer interrupting you to ask for clarifications.

You can probably also assume that the algorithm assessing your performance is sufficiently capable that it will be observing you at much the same level as a human interviewer. However, it is probably still worth speaking as clearly as possible with these kinds of interviews and paying extra attention to your lighting to ensure that your face is clearly visible.

No doubt the AIs scoring these interviews are improving all the time, but you still want to make their job as easy as possible. Just think about the same things as you would with a live Zoom interview, but more so.

9. How we can help

There are lots of great free resources on this site to get you started with preparation, from all our articles on case solving and consulting skills to our free case library and peer practice meeting board .

To step your preparation up a notch, though, our Case Academy course will give you everything you need to know to solve the most complex of cases - whether those are in live interviews, with chatbots, written tests or any other format.

Whatever kind of case you end up facing, nothing will bring up your skillset faster than the kind of acute, actionable feedback you can get from a mock case interview a real, MBB consultant. Whilst it's possible to get by without this kind of coaching, it does tend to be the biggest single difference maker for successful candidates.

You can find out more on our coaching page:

Explore Coaching

Of course, for those looking for a truly comprehensive programme, with a 5+ year experienced MBB consultant overseeing their entire prep personally, from networking and applications right through to your offer, we have our mentoring programmes.

You can read more here:

Comprehensive Mentoring

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Case interview maths (formulas, practice problems, and tips)

Today we’re going to give you everything you need in order to breeze through maths calculations during your case interviews. 

Becoming confident with maths skills is THE first step that we recommend to candidates like Karthik , who got an offer from McKinsey. 

And one of the first things you’ll need to know are the 6 core maths formulas that are used extensively in case interviews. 

Let’s dive in!

• Case interview maths formulas
• Must-know formulas
• Optional formulas
• Cheat sheet
• Practice questions
• Case maths apps and tools
• Tips and tricks
• Practice with experts

Click here to practise 1-on-1 with MBB ex-interviewers

1. case interview maths formulas, 1.1. must-know maths formulas.

Here’s a summarised list of the most important maths formulas that you should really master for your case interviews:

If you want to take a moment to learn more about these topics, you can read our in-depth article about  finance concepts for case interviews .

1.2. Optional maths formulas

In addition to the above, you may also want to learn the formulas below. 

Having an in-depth understanding of the business terms below and their corresponding formulas is NOT required to get offers at McKinsey, BCG, Bain and other firms. But having a rough idea of what they are can be handy.

EBITDA = Earnings Before Interest Tax Depreciation and Amortisation

EBIDTA is essentially profits with interest, taxes, depreciation and amortisation added back to it.

It's useful for comparing companies across industries as it takes out the accounting effects of debt and taxes which vary widely between, say, Meta (little to no debt) and ExxonMobil (tons of debt to finance infrastructure projects). More  here .

NPV = Net Present Value

NPV tells you the current value of one or more future cashflows. 

For example, if you have the option to receive one of the two following options, then you could use NPV to choose the more profitable option:

• Option 1 : receive $100 in 1 year and $100 in 2 years
• Option 2 : receive $175 in 1 year

If we assume that the interest rate is 5% then option 1 turns out to be slightly better. You can learn more about the formula and how it works  here .

Return on equity = Profits / Shareholder equity

Return on equity (ROE) is a measure of financial performance similar to ROI. ROI is usually used for standalone projects while ROE is used for companies. More  here .

Return on assets = Profits / Total assets

Return on assets (ROA) is an alternative measure to ROE and a good indicator of how profitable a company is compared to its total assets. More  here .

1.3 Case interview maths cheat sheet

If you’d like to get a free PDF cheat sheet that summarises the most important formulas and tips from this case interview maths guide, just click on the link below.

Download free pdf case interview maths cheat sheet

2. Case interview maths practice questions

If you’d like some examples of case interview maths questions, then this is the section for you!

Doing maths calculations is typically just one step in a broader case, and so the most realistic practice is to solve problems within the context of a full case.

So, below we’ve compiled a set of maths questions that come directly from  case interview examples  published by McKinsey and Bain. 

We recommend that you try solving each problem yourself before looking at the solution. 

Now here’s the first question!

2.1 Payback period - McKinsey case example

This is a paraphrased version of question 3 on  McKinsey’s Beautify practice case :

How long will it take for your client to make back its original investment, given the following data?

• After the investment, you’ll get 10% incremental revenue
• You’ll have to invest €50m in IT, €25m in training, €50m in remodeling, and €25m in inventory
• Annual costs after the initial investment will be €10m 
• The client’s annual revenues are €1.3b

Note: take a moment to try solving this problem yourself, then you can get the answer under  question 3 on McKinsey’s website . 

2.2 Cost reduction - McKinsey case example

This is a paraphrased version of question 2 on  McKinsey’s Diconsa practice case :

How much money in total would families in rural Mexico save per year if they could pick up benefits payments from Diconsa stores?

• Pick up currently costs 50 pesos per month for each family
• If pick up were available at Diconsa stores, the cost would be reduced by 30%
• Assume that the population of Mexico is 100m 
• 20% of Mexico’s population is in rural areas, and half of these people receive benefits
• Assume that all families in Mexico have 4 members

Note: take a moment to try solving this problem yourself, then you can get the answer under  question 2 on McKinsey’s website . 

2.3 Product launch - McKinsey case maths example

This is a paraphrased version of question 2 on  McKinsey’s Electro-Light practice case :

What share of the total electrolyte drink market would the client need in order to break even on their new Electro-Light drink product?

• The target price for Electro-Light is $2 for each 16 oz (1/8th gallon) bottle
• Electro-Light would require $40m in fixed costs
• Each bottle of Electro-Light costs $1.90 to produce and deliver
• The electrolyte drink market makes up 5% of the US sports-drink market
• The US sports-drink market sells 8b gallons of beverages per year

2.4 Pricing strategy - McKinsey case maths example

This is a paraphrased version of question 3 on  McKinsey’s Talbot Trucks practice case :

What is the highest price Talbot Trucks can charge for their new electric truck, such that the total cost of ownership is equal to diesel trucks? 

• Assume the total cost of ownership for all trucks consists of these 5 components: driver, depreciation, fuel, maintenance, other. 
• A driver costs €3k/month for diesel and electric trucks
• Diesel trucks and electric trucks have a lifetime of 4 years, and a €0 residual value
• Diesel trucks use 30 liters of diesel per 100km, and diesel fuel costs €1/liter
• Electric trucks use 100kWh of energy per 100km, and energy costs €0.15/kWh
• Annual maintenance is €5k for diesel trucks and €3k for electric trucks
• Other costs (e.g. insurance, taxes, and tolls) is €10k for diesel trucks and €5k for electric trucks
• Diesel trucks cost €100k

2.5 Inclusive hiring - McKinsey case maths example

This is a paraphrased version of question 3 on  McKinsey’s  Shops Corporation practice case :

How many female managers should be hired next year to reach the goal of 40% women executives in 10 years? 

• There are 300 executives now, and that number will be the same in 10 years
• 25% of the executives are currently women
• The career levels at the company (from junior to senior) are as follows: professional, manager, director, executive
• In the next 5 years, ⅔ of the managers that are hired will become directors. And in years 6-10, ⅓ of those directors will become executives. 
• Assume 50% of the hired managers will leave the company
• Assume that everything else in the company’s pipeline stays the same after hiring the new managers

2.6 Breakeven point - Bain case maths example

This is a paraphrased version of the calculation portion of  Bain’s Coffee Shop Co. practice case : 

How many cups of coffee does a newly opened coffee shop need to sell in the first year in order to break even?

• The price of coffee will be £3/cup
• Each cup of coffee costs £1/cup to produce 
• It will cost £245,610 to open the coffee shop
• It will cost £163,740/year to run the coffee shop

Note: take a moment to try solving this problem yourself, then you can get the answer  on Bain’s website .

2.7 Driving revenue - Bain case maths example

This is a paraphrased version of the calculation part of  Bain’s FashionCo practice case : 

Which option (A or B) will drive the most revenue this year?

Option A: Rewards program

• There are 10m total customers
• The avg. annual spend per person is $100 before any sale (assume sales are evenly distributed throughout the year)
• Customers will pay a $50 one-time activation fee to join the program
• 25% of customers will join the rewards program this year
• Customers who join the rewards program always get 20% off

Option B: Intermittent sales

• For 3 months of the year, all products are discounted by 20%
• During the 3 months of discounts, purchases will increase by 100%

3. Case maths apps and tools

In the case maths problems in the previous section, there were essentially 2 broad steps: 

• Set up the equation
• Perform the calculations

After learning the formulas earlier in this guide, you should be able to manage the first step. But performing the mental maths calculations will probably take some more practice. 

Mental maths is a muscle. But for most of us, it’s a muscle you haven’t exercised since high school. As a result, your  case interview preparation  should include some maths training.

If you don't remember how to calculate basic additions, substractions, divisions and multiplications without a calculator, that's what you should focus on first.

In addition, Khan Academy has also put together some helpful resources. Here are the ones we recommend if you need an in-depth arithmetic refresher:

• Additions and subtractions
• Multiplications and divisions
• Percentages

Scientific notation

Once you're feeling comfortable with the basics you'll need to regularly exercise your mental maths muscle in order to become as fast and accurate as possible.

• Preplounge's maths tool . This web tool is very helpful to practice additions, subtractions, multiplications, divisions and percentages. You can both sharpen your precise and estimation maths with it.
• Victor Cheng's maths tool . This tool is similar to the Preplounge one, but the user experience is less smooth in our opinion.
• Mental math cards challenge app  (iOS). This mobile app lets you work on your mental maths easily on your phone. Don't let the old school graphics deter you from using it. The app itself is actually very good.
• Mental math games  (Android). If you're an Android user this one is a good substitute to the mental math cards challenge one on iOS.

4. Case interview maths tips and tricks

4.1. calculators are not allowed in case interviews.

If you weren’t aware of this rule already, then you’ll need to know this: 

Calculators are not allowed in case interviews. This applies to both in-person and virtual case interviews. And that’s why it’s crucial for candidates to practice doing mental maths quickly and accurately before attending a case interview. 

And unfortunately, doing calculations without a calculator can be really slow if you use standard long divisions and multiplications. 

But there are some tricks and techniques that you can use to simplify calculations and make them easier and faster to solve in your head. That’s what we’re going to cover in the rest of this section. 

Let’s begin with rounding numbers.

4.2. Round numbers for speed and accuracy

The next 5 subsections all cover tips that will help you do mental calculations faster. Here’s an overview of each of these tips: 

And the first one that we’ll cover here is rounding numbers. 

The tricky thing about rounding numbers is that if you round them too much you risk:

• Distorting the final result
• Or your interviewer telling you to round the numbers less

Rounding numbers is more of an art than a science, but in our experience, the following two tips tend to work well:

• We usually recommend that you avoid rounding numbers by more than +/- 10%. This is a rough rule of thumb but gives good results based on conversations with past candidates.
• You also need to alternate between rounding up and rounding down so the effects cancel out. For instance, if you're calculating A x B, we would recommend rounding A UP, and rounding B DOWN so the rounding balances out.

Note that you won't always be able to round numbers. In addition, even after you round numbers the calculations could still be difficult. So let's go through a few other tips that can help in these situations.

4.3. Abbreviate large numbers

Large numbers are difficult to deal with because of all the 0s. To be faster you need to use notations that enable you to get rid of these annoying 0s. We recommend you use labels and the scientific notation if you aren't already doing so.

Labels (k, m, b)

Use labels for thousand (k), million (m), and billion (b). You'll write numbers faster and it will force you to simplify calculations. Let's use 20,000 x 6,000,000 as an example.

• No labels: 20,000 x 6,000,000 = ... ???
• Labels: 20k x 6m = 120k x m = 120b

This approach also works for divisions. Let's try 480,000,000,000 divided by 240,000,000.

• No labels: 480,000,000,000 / 240,000,000 = ... ???
• Labels: 480b / 240m = 480k / 240 = 2k

When you can't use labels, the scientific notation is a good alternative. If you're not sure what this is, you're really missing out. But fortunately, Khan Academy has put together a good primer on that topic  here .

• Multiplication example: 600 x 500 = 6 x 5 x 102 X 102 = 30 x 104 = 300,000 = 300k
• Division example: (720,000 / 1,200) / 30 = (72 / (12 x 3)) x (104 / (102 x 10)) = (72 / 36) x (10) = 20

When you're comfortable with labels and the scientific notation you can even start mixing them:

• Mixed notation example: 200k x 600k = 2 x 6 x 104 x m = 2 x 6 x 10 x b = 120b

4.4. Use factoring to make calculations simpler

To be fast at maths, you need to avoid writing down long divisions and multiplications because they take a LOT of time. In our experience, doing multiple easy calculations is faster and leads to less errors than doing one big long calculation.

A great way to achieve this is to factor and expand expressions to create simpler calculations. If you're not sure what the basics of factoring and expanding are, you can use Khan Academy again  here  and  here . Let's start with factoring.

Simple numbers: 5, 15, 25, 50, 75, etc.

In case interviews some numbers come up very frequently, and it's useful to know shortcuts to handle them. Here are some of these numbers: 5, 15, 25, 50, 75, etc. 

These numbers are common, but not particularly easy to handle.

For instance, consider 36 x 25. It's not obvious what the result is. And a lot of people would need to write down the multiplication on paper to find the answer. However there's a MUCH faster way based on the fact that 25 = 100 / 4. Here's the fast way to get to the answer:

• 36 x 25 = (36 / 4) x 100 = 9 x 100 = 900

Here's another example: 68 x 25. Again, the answer is not immediately obvious. Unless you use the shortcut we just talked about; divide by 4 first and then multiply by 100:

• 68 x 25 = (68 / 4) x 100 = 17 x 100 = 1,700

Factoring works both for multiplications and divisions. When dividing by 25, you just need to divide by 100 first, and then multiply by 4. In many situations this will save you wasting time on a long division. Here are a couple of examples:

• 2,600 / 25 = (2,600 / 100) x 4 = 26 x 4 = 104
• 1,625 / 25 = (1,625 / 100) x 4 = 16.25 x 4 = 65

The great thing about this factoring approach is that you can actually use it for other numbers than 25. Here is a list to get you started:

• 2.5 = 10 / 4
• 7.5 = 10 x 3 / 4
• 15 = 10 x 3 / 2
• 25 = 100 / 4
• 50 = 100 / 2
• 75 = 100 x 3 / 4

Once you're comfortable using this approach you can also mix it with the scientific notation on numbers such as 0.75, 0.5, 0.25, etc.

Factoring the numerator / denominator

For divisions, if there are no simple numbers (e.g. 5, 25, 50, etc.), the next best thing you can do is to try to factor the numerator and / or denominator to simplify the calculations. Here are a few examples:

• Factoring the numerator: 300 / 4 = 3 x 100 / 4 = 3 x 25 = 75
• Factoring the denominator: 432 / 12 = (432 / 4) / 3 = 108 / 3 = 36
• Looking for common factors: 90 / 42 = 6 x 15 / 6 x 7 = 15 / 7

4.5. Expand numbers to make calculations easier

Another easy way to avoid writing down long divisions and multiplications is to expand calculations into simple expressions.

Expanding with additions

Expanding with additions is intuitive to most people. The idea is to break down one of the terms into two simpler numbers (e.g. 5; 10; 25; etc.) so the calculations become easier. Here are a couple of examples:

• Multiplication: 68 x 35 = 68 x (10 + 25) = 680 + 68 x 100 / 4 = 680 + 1,700 = 2,380
• Division: 705 / 15 = (600 + 105) / 15 = (15 x 40) / 15 + 105 / 15 = 40 + 7 = 47

Notice that when expanding 35 we've carefully chosen to expand to 25 so that we could use the helpful tip we learned in the factoring section. You should keep that in mind when expanding expressions.

Expanding with subtractions

Expanding with subtractions is less intuitive to most people. But it's actually extremely effective, especially if one of the terms you are dealing with ends with a high digit like 7, 8 or 9. Here are a couple of examples:

• Multiplication: 68 x 35 = (70 - 2) x 35 = 70 x 35 - 70 = 70 x 100 / 4 + 700 - 70 = 1,750 + 630 = 2,380
• Division: 570 / 30 = (600 - 30) / 30 = 20 - 1= 19

4.6. Simplify growth rate calculations

You will also often have to deal with growth rates in case interviews. These can lead to extremely time-consuming calculations, so it's important that you learn how to deal with them efficiently.

Multiply growth rates together

Let's imagine your client's revenue is $100m. You estimate it will grow by 20% next year and 10% the year after that. In that situation, the revenues in two years will be equal to:

• Revenue in two years = $100m x (1 + 20%) x (1 + 10%) = $100m x 1.2 x 1.1 = $100m x (1.2 + 0.12) = $100m x 1.32 = $132m

Growing at 20% for one year followed by 10% for another year therefore corresponds to growing by 32% overall.

To find the compound growth you simply need to multiply them together and subtract one: (1.1 x 1.2) - 1= 1.32 - 1 = 0.32 = 32%. This is the quickest way to calculate compound growth rates precisely.

Note that this approach also works perfectly with negative growth rates. Let's imagine for instance that sales grow by 20% next year, and then decrease by 20% the following year. Here's the corresponding compound growth rate:

• Compound growth rate = (1.2 x 0.8) - 1 = 0.96 - 1 = -0.04 = -4%

See how growing by 20% and then shrinking by 20% is not equal to flat growth (0%). This is an important result to keep in mind.

Estimate compound growth rates

Multiplying growth rates is a really efficient approach when calculating compound growth over a short period of time (e.g. 2 or 3 years).

But let's imagine you want to calculate the effect of 7% growth over five years. The precise calculation you would need to do is:

• Precise growth rate: 1.07 x 1.07 x 1.07 x 1.07 x 1.07 - 1 = ... ???

Doing this calculation would take a lot of time. Fortunately, there's a useful estimation method you can use. You can approximate the compound growth using the following formula:

• Estimate growth rate = Growth rate x Number of years

In our example:

• Estimate growth rate: 7% x 5 years = 35%

In reality if you do the precise calculation (1.075 - 1) you will find that the actual growth rate is 40%. The estimation method therefore gives a result that's actually quite close. In case interviews your interviewer will always be happy with you taking that shortcut as doing the precise calculation takes too much time.

4.7. Memorise key statistics

In addition to the tricks and shortcuts we’ve just covered, it can also help to memorise some common statistics. 

For example, it would be good to know the population of the city and country where your target office is located. 

In general, this type of data is useful to know, but it's particularly important when you face  market sizing questions . 

So, to help you learn (or refresh on) some important numbers, here is a short summary:

Of course this is not a comprehensive set of numbers, so you may need to tailor it to your own location or situation.   

5. Practice with experts

Sitting down and working through the maths formulas we've gone through in this article is a key part of your case interview preparation. But it isn’t enough.

At some point you’ll want to practise making calculations under interview conditions.

You can try to do this with friends or family. However, if you really want the best possible preparation for your case interview, you'll also want to work with ex-consultants who have experience running interviews at McKinsey, Bain, BCG, etc.

If you know anyone who fits that description, fantastic! But for most of us, it's tough to find the right connections to make this happen. And it might also be difficult to practice multiple hours with that person unless you know them really well.

Here's the good news. We've already made the connections for you. We’ve created a coaching service where you can do mock interviews 1-on-1 with ex-interviewers from MBB firms. Learn more and start scheduling sessions today.

Related articles:

21 Interview Questions to Uncover Case Study Gold

Plus 7 interviewing dos and don'ts.

Asking the right interview questions is critical to producing an impactful B2B SaaS case study.

For the first time ever, we’ve decided to share the powerful interview questions we use when conducting a case study interview for a customer.

What you’ll find in the cheat sheet

• 21 questions you need to start asking in your case study interviews
• 3 interviewing tips to keep in mind
• 4 common interviewing mistakes to avoid

Case studies that resonate

With these 21 questions in your toolkit, you’ll be able to uncover nuggets of gold that will help you create a case study that truly resonates with your target audience.

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Case Interview Formulas: 6 Concepts You Need to Know

• Last Updated May, 2023

Are you preparing for a consulting interview and feeling overwhelmed by the math? Don’t worry; we’re here to help you master case interview formulas!

Consulting case interviews require mental math skills and prohibit calculators. However, you can conquer the case interview math formulas if you understand a few key business concepts and practice consistently.

In this article, we’ll discuss:

• What case interview formulas are
• Why case interview math formulas are important
• Top 6 concepts and formulas to know (bonus: case interview formula cheat sheet)
• Our 5 tips on how to master case interview formulas 

Let’s get started!

What are Consulting Case Interview Formulas

Top 6 case interview formulas you should know, 5 tips for practicing case interview formulas.

What is Management Consulting vs Strategy Consulting?

How To Decide If You Want To Be a Management or Strategy Consultant

How Top Firms Define Themselves

Top 4 Tips on Figuring Out What Firm is Right For You

Consulting case formulas are the quantitative frameworks used to evaluate real-world business problems. Testing these concepts in your case interview helps your interviewer assess your ability to think critically, analyze data, and communicate effectively. Applying these formulas can help you solve consulting cases, such as market sizing or cost savings.

Here’s the good news: Consulting case interview formulas aren’t like the boring math you learned in school. Instead, it’s all about getting insights that guide business decisions rather than calculating the correct answer to the 4th decimal point. So don’t worry if you weren’t the math whiz in your calculus class!

While the concepts are not particularly complex, you’ll need to be able to do the math calculations efficiently without a calculator or computer. You don’t want your interviewer to wait while you struggle to divide 1000 by 7!

Why Practicing the Skill of Case Interview Formulas Matters as a Consultant

A consultant often works against the clock, juggling multiple tasks and competing deadlines. In such a fast-paced environment, mental math is a skill that can help you estimate the answer, avoid wasting time on low-value work, and, ultimately, solve your client’s problems!

Being able to do mental math isn’t just about efficiency – it’s also about looking competent in front of clients and having productive conversations. After all, clients are paying a lot for your team’s expertise. When a client asks a basic question, you don’t want to frantically search for your calculator or fumble on Excel. 

Another reason why this skill is important in consulting is that it allows you to sense-check your answers. Excel formulas can break, databases may be incomplete, and mistakes can happen. By having a solid understanding of mental math and case interview formulas, you can spot errors before they lead you down the wrong path.

Mastering the case interview formula skill also frees up your brain power to focus on the broader answer. Instead of being bogged down by tedious calculations, you can devote more mental bandwidth to analyzing the problem, identifying key insights, and providing recommendations for the client. In other words, developing this skillset allows you to focus on what you enjoy about consulting: problem-solving for real business challenges!

Nail the case & fit interview with strategies from former MBB Interviewers that have helped 89.6% of our clients pass the case interview.

Let’s dive into the 6 case interview formulas that are common in consulting interviews and how to use them effectively.

Keep in mind that this list is not exhaustive, but it is a good foundation. During the interview, you’ll need to apply these formulas strategically and may need to combine them to solve the client’s problem.

To illustrate the following case interview formulas, we’ll use this problem:

Our client, SweetCo, is a candy company that manufactures gummies and hard candies. Over the past five years, they’ve noticed a decrease in profitability and have hired us to help them understand what’s wrong and how to fix it.

One of the most common case interview questions revolves around a company’s profitability. The goal is to figure out whether a company is making money or not, and what it can do to increase its bottom line.

Profit is the amount of money left over after a company has paid all its expenses and collected its revenue. It’s typically calculated over a set period, such as a quarter or a year. The formula is:

Profit = Revenues – Cost .

There are two main ways for companies to increase their profits: by bringing in more revenue or by cutting costs. 

In the case of SweetCo, their profits have gone down in the last 5 years. To figure out why, we’d need to take a closer look at both their revenues and their costs and see which one is driving the problem.

Revenue, also known as sales, is the total amount of money a company receives from selling its products or services. It’s always measured in terms of currency, such as U.S. dollars or European euros.

To calculate revenue, you’ll need to know the volume of products sold and the price at which they are sold. Depending on what data you have, you can use the formula:

Revenue = Volume x Price .

There are 2 types of costs: fixed and variable costs.

Fixed costs are expenses that do not change regardless of how much product or service is produced. Examples of SweetCo’s fixed costs include rent and management salaries. These costs do not change if SweetCo increases its candy production (unless it needs a whole new factory).

On the other hand, variable costs are expenses that increase with higher sales or production. For SweetCo, these could include costs for sugar, flavoring, and production labor.

To calculate the total cost, you add all costs together:

Total Cost = Fixed Costs + Variable Costs .

We recommend reading about the Profitability Framework If you want to learn more.

2. Profit Margins

Profit margin is a metric used to measure how much profit the company makes as a percentage of its revenue:

Profit Margin % = Profit / Revenue x 100

This is an essential metric for businesses because it helps them determine their pricing strategies and evaluate their financial health.

SweetCo’s profit margin decreased from 25% to 15% over the last 5 years. This indicates that the company is not operating as efficiently as it could be or that competition in their market is getting more intense. The profit margin is a useful tool to identify areas where the company could potentially improve its profitability.

There are 3 types of profit margins:

• Net profit margin measures the company’s overall profitability after all expenses, including taxes and interest, have been deducted from the revenue. This is the most common profit margin case interview formula you will use.
• Gross profit margin gives an idea of the profitability of the company’s core operations. It only considers the revenue and the cost of goods sold, which are the expenses incurred to produce the company’s product or service.
• Operating profit margin takes it one step further from the gross profit margin. It also takes into account other operating expenses, such as rent, utilities, etc. It excludes taxes and interest expenses.

Each of these types of profit margins provides a different perspective on a company’s financial performance. For example, if SweetCo’s gross profit margin is decreasing more than the operating profit margin, it may indicate that the costs of candy ingredients are driving the overall profitability problem, rather than fixed costs.

3. Breakeven

Breakeven, also known as the payback period, is a financial metric that helps companies determine how long it would take to recover their initial investment in a new project or investment. It is usually measured in years and is calculated by:

Breakeven or Payback Period = Initial Investment / Annual Profit .

For example, let’s say SweetCo is considering expanding into the chocolate market and building a new factory that costs $2 million. This factory is projected to generate an additional $250,000 in annual profit. Using the breakeven formula, we can calculate that it would take SweetCo 8 years to recoup its initial investment.

It’s important to note that breakeven analysis should not be the only factor considered when making business decisions. Other factors, such as market competition and potential future growth, should also be considered.

In the SweetCo case, improving operating efficiency to lower costs in the existing candy category could be a more feasible option for increasing profits than waiting 8 years to pay back the chocolate factory.

Return on Investment

A related concept to breakeven is the return on investment (ROI). This metric helps companies measure their investment’s effectiveness in generating additional profit.

Return on investment helps businesses determine whether or not an investment is worth the resources or to choose between alternative investments. A higher ROI means a better return on the investment, while a lower ROI means less profit generated relative to the investment cost.

SweetCo is considering investing $500,000 in a new packaging machine for their gummy candies. The machine will help reduce costs and increase efficiency. The expected annual savings from this investment is $75,000.

We would use the case interview formula:

Return on Investment % = (Profit from Investment / Investment Cost) x 100

= ($75,000 / $500,000) x 100% = 15%

This means that for every dollar SweetCo invests in the new packaging machine, they can expect to earn an additional 15 cents in profit. This ROI calculation can help SweetCo determine whether the new machine is worth pursuing, as they can compare the ROI to their desired return rate or compare it to other uses for their resources.

4. Market Size

Market size determines the number of potential customers for a product or service, as well as the revenue potential that comes with it. It helps businesses determine if investing in a new product or service is worth the costs. Additionally, market sizing helps businesses understand their target audience and their needs.

If SweetCo is considering expanding its product offerings to include chocolate, they need to determine the potential market size for chocolate to see if there are enough customers.

There are two ways to determine market size: the top-down and bottom-up approaches.

The top-down approach: We first look at the total number of households in our target market, the U.S. in this example. Our research finds there are 125 million households in the country. We estimate that about 70% of households are chocolate consumers.

125 million households x 70% = 87.5 million potential chocolate-consuming households in the U.S.

The bottom-up approach: SweetCo plans to introduce its chocolate products in five major cities in the United States: New York, Los Angeles, Chicago, Houston, and Philadelphia.

After research and analysis, we estimate about 3 million households in these 5 cities are chocolate consumers. A preliminary market survey suggests households spend an average of $50 a year on chocolate.

3 million households in target cities x $50 spent on chocolate per household per year = $150 million potential revenue in target cities.

Both approaches have pros and cons, but combining the two can lead to the most accurate estimate of market size. By using market size calculations, SweetCo can make informed decisions about whether to expand into the chocolate market and what resources to allocate to this new category.

We dive deep into How to Ace Market Sizing for more examples.

5. Market Share

Market share is the percentage of the total sales in a specific market the company makes. This metric can vary from 0%, which means the company has no presence in the market, to 100%, which signifies the company has complete dominance in the market. 

Calculating market share can also provide insights into potential challenges and opportunities for a company within the market. For example, if the company already has a high market share, it suggests there is limited room to grow in that market. Factors that impact market share include brand recognition, distribution, and pricing strategy.

Company’s Market Share = Company’s Revenue in the Market / Total Market Revenue

For example, if the chocolate market is worth $150 million and SweetCo believes it can generate $15 million in revenue, its market share would be 10%.

6. Growth Rates

Growth rate tells us how much a company’s revenue (or other metric) has increased or decreased over a period of time. We calculate it by comparing the current year’s revenue to the previous year’s. The formula is:

Growth Rate % = (New – Old) / Old x 100

For example, let’s say SweetCo had $100 million in revenue this year and $120 million in revenue last year. To calculate the revenue growth rate, we would use the formula:

Growth rate = ($100 million – $120 million) / $120 million = -0.17  x 100   = -17%

This means that SweetCo’s revenue has decreased by 17% from last year to this year.

The growth rate can be positive or negative. A negative growth rate would indicate a decrease in revenue, which is the problem SweetCo has noticed in the last 5 years.

Bonus: Case Interview Formula Cheat Sheet

If you are just starting to practice cases, we recommend printing this cheat sheet as a reference. Once you get comfortable, you should know the formulas by memory.

1. Know Your Basics

Refresh your knowledge of basic multiplication, division, addition, and subtraction. Know key fractions, such as ⅛ being equal to 0.125. 

Review and know how to use the six most common case interview formulas we covered in the previous section.

Remember that you are not allowed a calculator in most interviews, so you will have to rely on pen and paper.

2. Consistent Practice

Practice consistently! Other than case mock interviews, there are online resources for mental math drills. You can also practice in everyday life situations, such as calculating bills or grocery expenses without a calculator.

3. Clarify Concepts & Expectations with Your Interviewer

Ask your interviewer to clarify any confusing case contexts or concepts. For example, if it is a utility client, you can confirm how the company generates revenue.

At the beginning of your analysis, ask for permission to round numbers. Most interviewers will allow you to do this.

4. Try Different Mental Math Methods

Experiment with different mental math methods to make calculations easier for you. Use simple numbers (e.g., rounding to the nearest 1000) or scientific notations to visualize numbers. For example, if you need to divide 60,000,000 by 3,000,000, you can use the scientific notation method. First, rewrite it as (6 x 10^7) x (3 x 10^6). You can easily multiply the single digits (6 / 3 = 2). You can then subtract the exponents (7 – 6 = 1). Therefore, you are left with 2 x 10^1, which is 20.

Try different methods during your practice case interviews to find what works best for you.

5. Relate Your Analysis to the Case

Focus on the insights you can draw from the numbers and how they relate to the business problem you’re trying to solve. Explain what that number means in the context of the business problem and recommend a solution. 

You can impress your interviewer by knowing the nuances of the industry. For example, if the client is in mining, it’s typically important to know your return on investment on the heavy machinery. 

With consistent practice, you can master case interview formulas and land your dream consulting job! If you need more help, check out Our Ultimate Guide to Case Interview Prep .

– – – – –

In this article, we’ve covered:

• Understanding what case interview formulas are and their importance in consulting interviews
• Learning the top 6 concepts and formulas that you need to know, including a bonus cheat sheet
• 5 tips on how to master case interview math formulas

Still have questions?

If you have more questions about case interview formulas, leave them in the comments below. One of My Consulting Offer’s case coaches will answer them.

Other people prepping on case interview formulas found the following pages helpful:

• Our Ultimate Guide to Case Interview Prep
• Case Interview Math
• Market Sizing Questions
• Profitability framework

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Machine learning interview questions, download pdf.

Introduction

This page will guide you to brush up on the skills of machine learning to crack the interview.

Here, our focus will be on real-world scenario ML interview questions asked in Microsoft, Amazon, etc., And how to answer them.

Let’s get started!

Firstly, Machine Learning refers to the process of training a computer program to build a statistical model based on data. The goal of machine learning (ML) is to turn data and identify the key patterns out of data or to get key insights.

For example, if we have a historical dataset of actual sales figures, we can train machine learning models to predict sales for the coming future.

Why is the Machine Learning trend emerging so fast?

Machine Learning solves Real-World problems. Unlike the hard coding rule to solve the problem, machine learning algorithms learn from the data.

The learnings can later be used to predict the feature. It is paying off for early adopters.

A full 82% of enterprises adopting machine learning and Artificial Intelligence (AI) have gained a significant financial advantage from their investments.

According to Deloitte, companies have an impressive median ROI of 17%.

Machine Learning Interview Questions For Freshers

1. why was machine learning introduced.

The simplest answer is to make our lives easier. In the early days of “intelligent” applications, many systems used hardcoded rules of “if” and “else” decisions to process data or adjust the user input. Think of a spam filter whose job is to move the appropriate incoming email messages to a spam folder.  

But with the machine learning algorithms, we are given ample information for the data to learn and identify the patterns from the data.

Unlike the normal problems we don’t need to write the new rules for each problem in machine learning, we just need to use the same workflow but with a different dataset.

Let’s talk about Alan Turing, in his 1950 paper, “Computing Machinery and Intelligence”, Alan asked, “Can machines think?”

Full paper here

The paper describes the “Imitation Game”, which includes three participants -

• Human acting as a judge,
• Another human, and
• A computer is an attempt to convince the judge that it is human.

The judge asks the other two participants to talk. While they respond the judge needs to decide which response came from the computer. If the judge could not tell the difference the computer won the game.

The test continues today as an annual competition in artificial intelligence. The aim is simple enough: convince the judge that they are chatting to a human instead of a computer chatbot program.

2. What are Different Types of Machine Learning algorithms?

There are various types of machine learning algorithms. Here is the list of them in a broad category based on:

• Whether they are trained with human supervision (Supervised, unsupervised, reinforcement learning)
• The criteria in the below diagram are not exclusive, we can combine them any way we like.

3. What is Supervised Learning?

Supervised learning is a machine learning algorithm of inferring a function from labeled training data. The training data consists of a set of training examples.

Example: 01

Knowing the height and weight identifying the gender of the person. Below are the popular supervised learning algorithms. 

• Support Vector Machines
• Naive Bayes
• Decision Trees
• K-nearest Neighbour Algorithm and Neural Networks.

Example: 02

If you build a T-shirt classifier, the labels will be “this is an S, this is an M and this is L”, based on showing the classifier examples of S, M, and L.

4. What is Unsupervised Learning?

Unsupervised learning is also a type of machine learning algorithm used to find patterns on the set of data given. In this, we don’t have any dependent variable or label to predict. Unsupervised Learning Algorithms:

• Clustering, 
• Anomaly Detection, 
• Neural Networks and Latent Variable Models.

In the same example, a T-shirt clustering will categorize as “collar style and V neck style”, “crew neck style” and “sleeve types”.

5. What is ‘Naive’ in a Naive Bayes?

The Naive Bayes method is a supervised learning algorithm, it is naive since it makes assumptions by applying Bayes’ theorem that all attributes are independent of each other.

Bayes’ theorem states the following relationship, given class variable y and dependent vector x1  through xn:

P(yi | x1,..., xn) =P(yi)P(x1,..., xn | yi)(P(x1,..., xn)

Using the naive conditional independence assumption that each xiis independent: for all I this relationship is simplified to:

P(xi | yi, x1, ..., xi-1, xi+1, ...., xn) = P(xi | yi)

Since, P(x1,..., xn) is a constant given the input, we can use the following classification rule:

P(yi | x1, ..., xn) = P(y) ni=1P(xi | yi)P(x1,...,xn) and we can also use Maximum A Posteriori (MAP) estimation to estimate P(yi)and P(yi | xi) the former is then the relative frequency of class yin the training set.

P(yi | x1,..., xn)  P(yi) ni=1P(xi | yi)

y = arg max P(yi)ni=1P(xi | yi)

The different naive Bayes classifiers mainly differ by the assumptions they make regarding the distribution of P(yi | xi): can be Bernoulli, binomial, Gaussian, and so on.

Learn via our Video Courses

6. what is pca when do you use it.

Principal component analysis (PCA) is most commonly used for dimension reduction.

In this case, PCA measures the variation in each variable (or column in the table). If there is little variation, it throws the variable out, as illustrated in the figure below:

Thus making the dataset easier to visualize. PCA is used in finance, neuroscience, and pharmacology.

It is very useful as a preprocessing step, especially when there are linear correlations between features.

7. Explain SVM Algorithm in Detail

A Support Vector Machine (SVM) is a very powerful and versatile supervised machine learning model, capable of performing linear or non-linear classification, regression, and even outlier detection.

Suppose we have given some data points that each belong to one of two classes, and the goal is to separate two classes based on a set of examples.

In SVM, a data point is viewed as a p-dimensional vector (a list of p numbers), and we wanted to know whether we can separate such points with a (p-1)-dimensional hyperplane. This is called a linear classifier.

There are many hyperplanes that classify the data. To choose the best hyperplane that represents the largest separation or margin between the two classes.  If such a hyperplane exists, it is known as a maximum-margin hyperplane and the linear classifier it defines is known as a maximum margin classifier. The best hyperplane that divides the data in H3

We have data (x1, y1), ..., (xn, yn), and different features (xii, ..., xip), and yiis either 1 or -1.

The equation of the hyperplane H3 is the set of points satisfying:

Where w is the normal vector of the hyperplane. The parameter b||w||determines the offset of the hyperplane from the original along the normal vector w

So for each i, either xiis in the hyperplane of 1 or -1. Basically, xisatisfies:

w . xi - b = 1  or   w. xi - b = -1

8. What are Support Vectors in SVM?

A Support Vector Machine (SVM) is an algorithm that tries to fit a line (or plane or hyperplane) between the different classes that maximizes the distance from the line to the points of the classes.

In this way, it tries to find a robust separation between the classes. The Support Vectors are the points of the edge of the dividing hyperplane as in the below figure.

9. What are Different Kernels in SVM?

There are six types of kernels in SVM:

• Linear kernel - used when data is linearly separable. 
• Polynomial kernel - When you have discrete data that has no natural notion of smoothness.
• Radial basis kernel - Create a decision boundary able to do a much better job of separating two classes than the linear kernel.
• Sigmoid kernel - used as an activation function for neural networks.

10. What is Cross-Validation?

Cross-validation is a method of splitting all your data into three parts: training, testing, and validation data. Data is split into k subsets, and the model has trained on k-1of those datasets.

The last subset is held for testing. This is done for each of the subsets. This is k-fold cross-validation. Finally, the scores from all the k-folds are averaged to produce the final score.

11. What is Bias in Machine Learning?

Bias in data tells us there is inconsistency in data. The inconsistency may occur for several reasons which are not mutually exclusive.

For example, a tech giant like Amazon to speed the hiring process they build one engine where they are going to give 100 resumes, it will spit out the top five, and hire those.

When the company realized the software was not producing gender-neutral results it was tweaked to remove this bias.

12. Explain the Difference Between Classification and Regression?

Classification is used to produce discrete results, classification is used to classify data into some specific categories. For example, classifying emails into spam and non-spam categories. 

Whereas, regression deals with continuous data. For example, predicting stock prices at a certain point in time.

Classification is used to predict the output into a group of classes.  For example, Is it Hot or Cold tomorrow?

Whereas, regression is used to predict the relationship that data represents.  For example, What is the temperature tomorrow?

Advanced Machine Learning Questions

1. what is f1 score how would you use it.

Let’s have a look at this table before directly jumping into the F1 score.

In binary classification we consider the F1 score to be a measure of the model’s accuracy. The F1 score is a weighted average of precision and recall scores.

F1 = 2TP/2TP + FP + FN

We see scores for F1 between 0 and 1, where 0 is the worst score and 1 is the best score.  The F1 score is typically used in information retrieval to see how well a model retrieves relevant results and our model is performing.  

2. Define Precision and Recall?

Precision and recall are ways of monitoring the power of machine learning implementation. But they often used at the same time.

Precision answers the question, “Out of the items that the classifier predicted to be relevant, how many are truly relevant?”

Whereas, recall answers the question, “Out of all the items that are truly relevant, how many are found by the classifier?

In general, the meaning of precision is the fact of being exact and accurate. So the same will go in our machine learning model as well. If you have a set of items that your model needs to predict to be relevant. How many items are truly relevant?

The below figure shows the Venn diagram that precision and recall.

Mathematically, precision and recall can be defined as the following:

precision = # happy correct answers/# total items returned by ranker

recall = # happy correct answers/# total relevant answers

3. How to Tackle Overfitting and Underfitting?

Overfitting means the model fitted to training data too well , in this case, we need to resample the data and estimate the model accuracy using techniques like k-fold cross-validation.

Whereas for the Underfitting case we are not able to understand or capture the patterns from the data, in this case, we need to change the algorithms, or we need to feed more data points to the model.

4. What is a Neural Network?

It is a simplified model of the human brain. Much like the brain, it has neurons that activate when encountering something similar.

The different neurons are connected via connections that help information flow from one neuron to another.

5. What are Loss Function and Cost Functions? Explain the key Difference Between them?

When calculating loss we consider only a single data point, then we use the term loss function.

Whereas, when calculating the sum of error for multiple data then we use the cost function. There is no major difference.

In other words, the loss function is to capture the difference between the actual and predicted values for a single record whereas cost functions aggregate the difference for the entire training dataset.

The Most commonly used loss functions are Mean-squared error and Hinge loss.

Mean-Squared Error(MSE): In simple words, we can say how our model predicted values against the actual values.

Hinge loss: It is used to train the machine learning classifier, which is

L(y) = max(0,1- yy)

Where y = -1 or 1 indicating two classes and y represents the output form of the classifier. The most common cost function represents the total cost as the sum of the fixed costs and the variable costs in the equation y = mx + b

6. What is Ensemble learning?

Ensemble learning is a method that combines multiple machine learning models to create more powerful models.

There are many reasons for a model to be different. Few reasons are:

• Different Population
• Different Hypothesis
• Different modeling techniques

When working with the model’s training and testing data, we will experience an error. This error might be bias, variance, and irreducible error.

Now the model should always have a balance between bias and variance, which we call a bias-variance trade-off.

This ensemble learning is a way to perform this trade-off.

There are many ensemble techniques available but when aggregating multiple models there are two general methods:

• Bagging, a native method: take the training set and generate new training sets off of it.
• Boosting, a more elegant method: similar to bagging, boosting is used to optimize the best weighting scheme for a training set.

7. How do you make sure which Machine Learning Algorithm to use?

It completely depends on the dataset we have. If the data is discrete we use SVM. If the dataset is continuous we use linear regression.

So there is no specific way that lets us know which ML algorithm to use, it all depends on the exploratory data analysis (EDA).

EDA is like “interviewing” the dataset; As part of our interview we do the following:

• Classify our variables as continuous, categorical, and so forth. 
• Summarize our variables using descriptive statistics. 
• Visualize our variables using charts.

Based on the above observations select one best-fit algorithm for a particular dataset.

8. How to Handle Outlier Values?

An Outlier is an observation in the dataset that is far away from other observations in the dataset. Tools used to discover outliers are

• Scatter plot, etc.

Typically, we need to follow three simple strategies to handle outliers:

• We can drop them. 
• We can mark them as outliers and include them as a feature. 
• Likewise, we can transform the feature to reduce the effect of the outlier.

9. What is a Random Forest? How does it work?

Random forest is a versatile machine learning method capable of performing both regression and classification tasks.

Like bagging and boosting, random forest works by combining a set of other tree models. Random forest builds a tree from a random sample of the columns in the test data.

Here’s are the steps how a random forest creates the trees:

• Take a sample size from the training data.
• Begin with a single node.
• If the number of observations is less than node size then stop.
• Select random variables.
• Find the variable that does the “best” job of splitting the observations.
• Split the observations into two nodes.
• Call step `a` on each of these nodes.

10. What is Collaborative Filtering? And Content-Based Filtering?

Collaborative filtering is a proven technique for personalized content recommendations. Collaborative filtering is a type of recommendation system that predicts new content by matching the interests of the individual user with the preferences of many users.

Content-based recommender systems are focused only on the preferences of the user. New recommendations are made to the user from similar content according to the user’s previous choices.

11. What is Clustering?

Clustering is the process of grouping a set of objects into a number of groups. Objects should be similar to one another within the same cluster and dissimilar to those in other clusters.

A few types of clustering are:

• Hierarchical clustering
• K means clustering
• Density-based clustering
• Fuzzy clustering, etc.

12. How can you select K for K-means Clustering?

There are two kinds of methods that include direct methods and statistical testing methods:

• Direct methods: It contains elbow and silhouette 
• Statistical testing methods: It has gap statistics.

The silhouette is the most frequently used while determining the optimal value of k.

13. What are Recommender Systems?

A recommendation engine is a system used to predict users’ interests and recommend products that are quite likely interesting for them.

Data required for recommender systems stems from explicit user ratings after watching a film or listening to a song, from implicit search engine queries and purchase histories, or from other knowledge about the users/items themselves.

14. How do check the Normality of a dataset?

Visually, we can use plots. A few of the normality checks are as follows:

• Shapiro-Wilk Test
• Anderson-Darling Test
• Martinez-Iglewicz Test
• Kolmogorov-Smirnov Test
• D’Agostino Skewness Test

15. Can logistic regression use for more than 2 classes?

No, by default logistic regression is a binary classifier, so it cannot be applied to more than 2 classes. However, it can be extended for solving multi-class classification problems (multinomial logistic regression)

16. Explain Correlation and Covariance?

Correlation is used for measuring and also for estimating the quantitative relationship between two variables.  Correlation measures how strongly two variables are related. Examples like, income and expenditure, demand and supply, etc.

Covariance is a simple way to measure the correlation between two variables. The problem with covariance is that they are hard to compare without normalization.

17. What is P-value?

P-values are used to make a decision about a hypothesis test. P-value is the minimum significant level at which you can reject the null hypothesis. The lower the p-value, the more likely you reject the null hypothesis.

18. What are Parametric and Non-Parametric Models?

Parametric models will have limited parameters and to predict new data, you only need to know the parameter of the model.

Non-Parametric models have no limits in taking a number of parameters, allowing for more flexibility and to predict new data. You need to know the state of the data and model parameters.

19. What is Reinforcement Learning?

Reinforcement learning is different from the other types of learning like supervised and unsupervised. In reinforcement learning, we are given neither data nor labels. Our learning is based on the rewards given to the agent by the environment.

20. Difference Between Sigmoid and Softmax functions?

The sigmoid function is used for binary classification. The probabilities sum needs to be 1. Whereas, Softmax function is used for multi-classification. The probabilities sum will be 1.

The above-listed questions are the basics of machine learning. Machine learning is advancing so fast hence new concepts will emerge. So to get up to date with that join communities, attend conferences, read research papers. By doing so you can crack any ML interview.

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Google Cloud Platform (GCP) Interview Questions 2024

Amongst the most prominent cloud service providers, Google Cloud Platform (GCP) has grown rapidly through offering an extensive selection of solutions and services tailored to various business needs. It can be hard to get ready for a GCP interview if you are a beginner who only recently started out with cloud technology, a seasoned professional hoping to expand your expertise, or an intermediate level applicant looking to hone your skills.

Why focus on GCP?

GCP enables businesses of all sizes using reliable, scalable, and inexpensive options. It offers anything from databases, storage solutions, and computing the capacity to advanced machine learning, data analytics, and Web of Things services. Apart than rendering you a valued asset in the tech sector, understanding GCP opens up a lot of possibilities for advancement in your career.

How to Use This Guide

For every ability level, this guide provides an extensive set of questions in addition to explanations to help you understand the fundamental concepts. Make the most of these questions to evaluate what you’ve learned, identify areas that need work, and get comfortable with effectively expressing what you think you understand.

Preparing for the Interview

If you want to be prepared for anything for a GCP interview:

• Study GCP Documentation : The official Google documentation is an extensive resource covering all aspects of its cloud services.
• Hands-On Practice : For a practical knowledge, use the GCP sandbox environments or free tier account.
• Join Community Forums : Join in forums and groups with other GCP users to exchange knowledge and get knowledge from their experiences.
• Take Online Courses : A comprehensive knowledge of GCP can be acquired via a variety of online courses and certifications.

Basic GCP Interview Questions For Freshers

1. what is google cloud platform (gcp).

Google offers an assortment of cloud computing services using the Google Cloud Platform (GCP) name. It provides an array of services, including like machine learning, storage, and computational power, which assist companies develop, implement, and expand their applications. Global network support and compatibility into multiple Google products are included in GCP. It is created to be extremely secure and perform well for businesses of all sizes.

2. Name some core services provided by GCP.

Compute Engine for virtual machines, Cloud Storage for scalable object storage, BigQuery for data warehousing and analytics, and Kubernetes Engine for container orchestration are just a few of the primary offerings offered by the Google Cloud Platform (GCP).

3. What is Google Compute Engine?

Using Google Compute Engine (GCE), consumers may create and manage virtual machines on Google’s infrastructure utilizing a cloud-based service. It offers scalable computing power for various tasks and workloads. GCE supports an array of operating systems and configurations and interfaces with other Google Cloud services. It provides reliability, safety, and flexibility for cloud application and service installation.

4. Explain the purpose of Google Cloud Storage.

A service for storing and accessing data on Google’s infrastructure is Google Cloud Storage. It provides both structured and unstructured data with scalable, safe, and permanent options for storage. Through an easy API, users can save and retrieve objects of any size. Large data sets can be distributed, preserved, and backed up with simplicity utilizing it.

5. What are the different types of GCP projects?

Projects using Google Cloud Platform (GCP) can be grouped into several types: compute projects, which take advantage of services like Compute Engine and Kubernetes Engine; storage projects, that make employ of Cloud Storage and Bigtable; data analytics projects, that make use of BigQuery and Dataflow; and machine learning projects, that constitute utilize of AI Platform and AutoML. Each type improves performance and resource management through being appropriate for specific tasks and requirements.

6. How do you create a new project in GCP?

Go to console.cloud.google.com to get logged into the Google Cloud Console.

• Select “New Project” from the option list located at the very top of the page following click on its.
• Select a billing account, enter the project name, and specify the location or organization.
• To finish the configuration of the new project, click “Create.”

7. What is Google App Engine?

A number of Google Cloud’s fully managed platform-as-a-service (PaaS) products is Google App Engine. It renders feasible for developers to create and execute scalable web services and applications. Scaling, load balancing, and monitoring are just some of the infrastructure challenges which the platform takes deal of. Several programming languages are available, including Go, Java, Python, and Node.js.

8. What is the difference between a region and a zone in GCP?

A region is a distinct geographic area composed from multiple zones. Within a region, a zone is a separated data center which provides resources for fault tolerance and high availability. Zones enable redundancy within an area, while regions allow resources to be dispersed worldwide. In the case of a failure, this setup helps maintain service continuity and balance the load.

9. How does Google Cloud IAM help manage access?

Centralized control over who has access to specific assets is made feasible by Google Cloud IAM (Identity and Access Management). It helps you offer users, groups, and service accounts greater control over their access. IAM improves security through restricting access to whatever is necessary and helping in ensuring the application of the least privilege principle. It additionally offers extensive access control auditing and monitoring capabilities.

10. What is a VPC (Virtual Private Cloud)?

Within a cloud environment, a virtual network dedicated to a specific company is called a Virtual Private Cloud (VPC). It offers separated resources with restricted access and security instructions, including storage and compute instances. Using virtualized private clouds (VPCs), businesses may create their own logically isolated part of a cloud provider’s infrastructure. They offer you control over networking configurations and provide secure conditions for providing and running applications.

11. What is a firewall rule in GCP, and how does it control traffic to and from VM instances?

A firewall rule in Google Cloud Platform (GCP) is a set of criteria that dictates which incoming and outgoing network traffic is allowed to reach or leave VM instances. It controls traffic based on factors like IP addresses, protocols, and ports. By defining specific rules, administrators can restrict or permit traffic flow, enhancing security and network management within GCP environment.

Intermediate GCP Interview Questions

12. explain the purpose and use of google kubernetes engine (gke)..

A managed platform for carrying out, regulating, and expanding Kubernetes-based containerized applications is Google Kubernetes Engine (GKE). It opens developers from worrying about infrastructure and lets them focus on creating applications by automated an array of Kubernetes cluster management tasks. The features that GKE provides like as load balancing, auto-scaling, and automated updates, enable the running of containerized workloads in production environments. Teams may quickly deploy and upkeep apps at scale thanks to its encapsulation of the difficulties involved in building up and managing Kubernetes clusters. GKE is a popular tool for creating and managing cloud-native, contemporary apps. This is the architecture of Kubernetes. A managed platform for carrying out, regulating, and expanding Tectonic-based containerized applications is Google Kubernetes Engine (GKE). Many aspects of handling a Kubernetes cluster are automated by it, allowing developers to concentrate on creating apps rather than

13. What are Google Cloud Functions, and when would you use them?

Users may execute code in response to events triggered by Google Cloud services or external sources utilizing serverless, event-driven Google Cloud Functions. They provide a scalable and inexpensive way to executing brief sections of code without having to worry with managing infrastructure. Use them for jobs where you need to respond to events quickly and efficiently without annoying about server management, such as data processing, automation, or creating lightweight APIs.

14. How do you configure autoscaling in GCP?

For setting up autoscaling on Google Cloud Platform (GCP) , open the GCP Console then go to the Compute Engine section. Following that, choose the instance group you want to set up autoscaling for. Following that, select the metric or metrics to scale according to (such as CPU utilization or load balancing capacity) simply clicking on “Autoscaling.” Following adjusting for any pertinent parameters, particularly the minimum and maximum number of instances, save the configuration. From now on, GCP will adjust the quantity of instances based to the selected metrics.

15. What is Google Cloud Pub/Sub, and how does it work?

A messaging service for event-driven systems is Google Cloud Pub/Sub. It allows separate applications to interact synchronously with one another. Topics are conduits for distributing data; publishers communicate messages to these topics, and subscribers receive messages from these topics. It offers a variety of integrations within the Google Cloud ecosystem and scales automatically to manage enormous throughput. It uses a push-pull model, so users can choose to receive messages immediately via push notifications or pull them at their own acceleration.

16. Describe how to set up a Cloud SQL instance.

To set up a Cloud SQL instance:

• Navigate to the Google Cloud Console.
• Choose the project whereby the instance is to be generated.
• Click “Create Instance” after choosing SQL in the menu to the left.
• Choose the instance type, database engine, and options for configuration.
• To start your Cloud SQL instance, click “Create.”

17. What is the difference between Persistent Disk and Local SSD in GCP?

For data that has to survive more than the life of a single Compute Engine instance, Google Cloud Platform’s (GCP) Persistent Disk offers strong block storage. Redundancy and high availability are advantages it provides. Local SSD, on the other hand, offers temporary block storage which is high-performance, low-latency, and actually linked to the actual hardware operating the virtual machine instance. While local SSD works better, data stored on it is not as durable and will be lost in the event that the instance is terminated or suffers a failure.

18. How do you use Stackdriver for monitoring and logging in GCP?

Enabling the Stackdriver Monitoring and Logging APIs for your project is the initial step towards employing Stackdriver for monitoring and logging on Google Cloud Platform (GCP). Following that, set up Stackdriver Monitoring to offer dashboards and alerts for the metrics of your resources. For logging, submit your application logs to Stackdriver Logging, offering effective log data analysis, searching, and export. Additionally, for distributed application tracing for performance analysis, use Stackdriver Trace. Finally, confirm that appropriate IAM permissions are configured so as to access Stackdriver resources.

19. Explain the role of BigQuery in GCP.

BigQuery is the entirely managed serverless data storage solution offered by Google Cloud Platform. Using SQL-like queries, this enables users to study huge data sets quickly. Real-time analytics and insights are rendered feasible by BigQuery’s perfect handling of scalability. Integration with other GCP services makes data processing, visualization, and input easier. All sizes of companies may profit from BigQuery’s cost-effective pay-as-you-go membership model.

20. What is the principle of least privilege, and how do you apply it in GCP?

Due to the least privilege principle, users ought to receive only the bare minimum of access necessary to do their tasks. This is carried out in Google Cloud Platform (GCP) by giving users roles that have specific permissions, so limiting their access to only what they require. Roles can be carefully adjusted to grant specific permissions through IAM (Identity and Access Management) policies, limiting the likelihood of unauthorized behaves and potential security breaches.

21. Describe the process of setting up a VPN between an on-premises network and GCP.

Using the Cloud Console, establish a VPN gateway in Google Cloud Platform (GCP) firstly.

• Connect the on-premises network’s VPN device for the GCP VPN gateway through a virtual private network (VPN) connection.
• Put up the necessary firewall rules to ensure that communications is allowed between the VPN networks.
• Check the right routing is configured for the VPN for routing traffic between the on-premises and GCP networks.
• To guarantee that data can be transmitted effectively between the on-premises network and GCP resources, test the connection.

22. Explain the concept of uptime checks and how they contribute to monitoring in GCP.

GCP uptime checks are automated tests that maintain a watch on a resource’s or service’s availability. They test the responsiveness of a particular endpoint through sending requests to it on an ongoing basis. Uptime checks aid in maintaining service reliability and timely resolution of possible issues such as outages or problems with performance. In the realm of cloud computing, high availability and short downtime are crucial for user experience and business continuity. This proactive monitoring approach helps to achieve both of these goals.

Advanced GCP Interview Questions

23. how do you optimize the cost of running workloads in gcp.

Take the advantage of sustain to use the discount to decrease the cost of running workloads in the google cloud platform and application committed to use agreements for expected load. To significantly preserve the costs, use discovering virtual machines (VMs) for useless tasks. Use resource autoscaling to reach the demand while prevent the overprovisioning. Frequently review your instances and change the size according to nee of usage patterns. Use Google’s cost-management resources, include the Cost Explorer and Budget Alerts, to maintain an eye on and regulate billing.

24. Explain the concept of Infrastructure as Code (IaC) in GCP and tools you can use.

Configuration files are employed in Google Cloud Platform (GCP) Infrastructure as Code (IaC) to manage and provision cloud resources. This makes it practical to create repeatable and consistent setups utilize the code as opposed to people processes. Ansible for cloud resource automation and orchestration, Terraform for declarative resource management, and Google Cloud Deployment Manager for native templated deployments are essential to the instruments for Infrastructure as a Cloud (IaC) in GCP. These tools enable increase scalability, dependability, and automate the infrastructure procedures.

25. How would you design a highly available and scalable architecture in GCP?

Developing a scalable and highly available architecture in GCP includes:

• Use a global load balancer to distribute traffic between multi region.
• Deploy virtual machine instances across multiple location’s and regions with auto scale enabled on.
• Utilize the managed services like Cloud SQL database, BigQuery, and Firebase for backend operations.
• Combine cloud storage and cloud content delivery network for scaling, deploy content delivery globally.
• Combine cloud login and monitor for the routine upkeep and improve the performance.

26. Describe a multi-cloud strategy and how you can implement it using GCP.

A multi-cloud look at involves making use using different cloud services from the different providers to improve repetition, decrease expenses, and prevent vendor lock-in. This works with google cloud via BigQuery Omni for data analytics, Apigee to handle APIs across different environments, and Google Cloud’s Anthos for consistent management across clouds. Kubernetes Engine for orchestration, Virtual private cloud peering, and interconnects can all to be used to controlee integration with different cloud service providers. This approach to ensures uninterrupted communication and a combine management interface.

27. How do you ensure data security and compliance in GCP?

To ensure the data security and compliance in the Google Cloud Platform (GCP), it is an important to use identity and access management (IAM) to controls freedoms, allow audit logging to track and monitor the action, and encrypt the data when it is in transit and at rest. It is important to frequently install security patches and updates in addition to use the GCP’s integrated safety solutions, such Security Command Center, for threat detection and compliance checks. In addition, periodic security inspections and compliance to compliance regulations (like GDPR and HIPAA) ensure continuous compliance and security.

28. Explain the steps to migrate an existing on-premises application to GCP.

• Assessment and Planning: Analyze the application architecture as exists, the performance specifications, and the dependencies. Plan the migration strategy considering into consideration replatforming, rehosting, and refactoring.
• Provisioning GCP Resources: Building the necessary infrastructure on Google Cloud Platform (GCP) employing Virtual Machines (Compute Engine), Google Kubernetes Engine (GKE), or App Engine. This involves network, storage, and database architecture.
• Data Migration: To transfer data from the on-premises storage to google cloud platform, use the services like database migration or Google Cloud Storage Transfers Services.
• Application Deployment: After ensuring that each part has been set up and optimize the cloud, we can launch the application within the GCP environment.
• Testing and Optimization: Thoroughly test the application in the google cloud environment, maintain a close eye on performance, and implement any required changes to optimize for security, scalability, and cost-effectiveness.

29. How do you implement CI/CD pipelines in GCP?

To implement continuous integrations and continuous deployments CI/CD pipelines in usage under GCP:

• Source Code Management : Make advantage of Google Cloud Source Repositories or GitHub/Bitbucket connectivity.
• Continuous Integration : Automate the code packaging, testing, and deployment using the Google Cloud Build.
• Artifact Storage : Build artifacts may be kept in Google Cloud Storage, Artifact Registry or the Container Registry.
• Continuous Deployment : Use the Google Cloud Deploy or Cloud Run for automatic deployment to GKE, the App Engine, or Cloud Runs.
• Monitoring : Using Google Cloud Monitor and Logging to keep tabs on the performance and health of your cloud deployment.

30. What are Managed Instance Groups (MIGs), and how do you use them?

Controlled Instance Groups, or MIGs for simple terms, are groups of virtual instances in Google Cloud that are managed as a single entity. The next one is an autonomous instance that may grow and cure self. Managed instance group (MIGs) may ensure high availability by distribute the instances across multiple zones. By develop a group, establish its template, establishing scaling the instructions, and carry out it, they are used. It is easier to increase the capacity of MIGs while handling significant workloads effectively.

31. How do you design and manage data pipelines using GCP services?

Determining your data flow requirements is the first stage in develop and handle data pipelines on Google Cloud Platform. Employ the Cloud Storage for data storage, BigQuery for analytics, and Google Cloud Dataflow for batch and stream processing. Using the Cloud Composer to set up and track workflows. Use best practices for the data governance, security, and scalability throughout the pipeline. Sustain performance monitoring and improvement for the most important data processing.

32. Explain how you would handle disaster recovery and backup strategies in GCP.

I would start disaster recovery by transferring very important data to multiple regions using services like Cloud Storage and Cloud SQL. Putting up automated backups using applications like Cloud Snapshot for virtual machines or Cloud SQL automate the backups will be the next step. In addition, a multi-region load balancing and failover process was set up using Traffic Director to guarantee uninterrupted service availability. To be sure backups and recovery plans work correctly, they must be tested on a regularly. Last but not the least, moving virtual machines using Cloud Endure, one of Google’s managed services, helps improves the recovery efforts following an crucial time.

33. What are some common use cases for SSH tunneling in GCP?

• Secure Remote Access : Secure remote access to resources like virtual machines and databases can be achieved with Google Cloud Platform (GCP) via secure shell (SSH) tunneling.
• Proxying Traffic : It is frequently employed for secure proxy traffic between a local computer and google cloud-deployed resources, such as Kubernetes clusters.
• Database Connection : Secure connections to databases such as Cloud SQL can be created from local development environments via SSH tunneling.
• Bypassing Firewalls : It can be utilized for securely access internal GCP resources from external networks without avoiding firewalls.
• Secure File Transfer : Using SCP or SFTP, SSH tunneling allows safe file transfers between local machines and the Google Cloud Platform instances.

34. Explain the role of Cloud Armor in protecting applications deployed on Google Cloud Platform.

A safety precaution on the Google Cloud Platform called Cloud Armor protects the web apps from Distributed Denial-of-Service (DDoS) assaults and other online risks. By enable the users to set up and enforce security policies at the outer limits of the Google Cloud network, it acts as a means of defense. Applications’ availability and integrity are ensured by Cloud Armor’s features, that also assist reduce the risks. These capabilities includes geo-based access controls, IP whitelisting, and blacklisting.

35. What is the difference between Cloud Router and VPN tunnels in GCP?

The Cloud Router enable the dynamic routing between the networks within your Virtual Private Cloud (VPC) and other networks. Routes to your VPC networks are automatically offered by that fully managed a solution. Virtual private network tunnels, on the other hand, use encrypted communication over the open internet to offer safe connections between your VPC network and your on-premises network. VPN tunnels securely increase your network into on-premises environments, while Cloud Router handles routing within Google Cloud Platform.

36. What is the difference between GCP and AWS?

Google Cloud Platform (GCP) stands out among cloud service providers by offering a comprehensive array of scalable, secure, and cost-effective solutions tailored to diverse business needs. Understanding GCP can significantly enhance your career prospects in the tech industry. Preparing for a GCP interview requires a thorough study of its documentation, hands-on practice, and active participation in community forums. Leveraging online courses and engaging with various GCP services and tools will ensure you’re well-equipped to tackle interview questions at any skill level. Embrace the potential of GCP to unlock new opportunities and advance your expertise in cloud computing.

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