Case Interview Prep Guide (5 steps to an offer at MBB)

Are you preparing for a case interview at McKinsey, BCG, Bain, or another consulting firm? To land an offer, you’ll need to show that you can break down unfamiliar business problems, analyse data, and communicate clear recommendations.

I’m a former Bain consultant with 7+ years of experience across consulting, strategy, and operations. Over the past five years, I’ve coached candidates preparing for case interviews at leading consulting firms.

In this guide, I’d like to share the techniques I teach my clients to help them approach cases in a more structured and analytical way. I’ll walk you through each stage of a case interview using a real M&A example, explain how to use frameworks properly, and share some of my best tips along the way.

Here’s an overview of what we’ll cover:

• Step 1: Learn what to expect in a consulting case interview
• Step 2: Learn a structured approach to solving cases
• Step 3: Solve practice cases
• Step 4: Improve your case interview technique
• Step 5: Practise, practise, practise

Let’s get started!

Step 1: Learn what to expect in a consulting case interview↑

Before we get into the framework, let's make sure that we're all on the same page about what to expect in a case interview.

1.1 What is a case interview?

Case interviews (sometimes called case study interviews) are 1-hour assessments used by consulting firms to test candidates' problem-solving, maths, communication, and business acumen. They also come up in BizOps interview questions guide.

During the interview, you will be presented with a case study about an imaginary company facing a problem or challenge. You'll need to review the information, ask questions to get more information, and then provide recommendations on what actions the company should take.

Case interviews aim to simulate, as accurately as possible, the day-to-day of a management consultant. To make it as realistic as possible, interviewers often use questions from actual situations they've experienced with clients. 

If a candidate does well, the interviewer can be fairly confident that they've got what it takes to succeed in the role and represent the brand that the company carries.

1.2 What is the format of a case interview?

Most case interviews include a combination of these seven components, each designed to test a specific set of skills. 

1. Case prompt: tests your ability to filter information and focus on a relevant topic
2. Framework development: tests your problem-solving skills
3. Framework exploration: tests your problem-solving skills
4. Quantitative question: tests your quantitative and analytical ability
5. Brainstorming: tests your creative thinking skills
6. Recommendation: tests your business sense

The components and their order will vary depending on the case. There can also be smaller differences between the processes at firms. For example, Bain cases tend to include more charts than cases at some other firms.

Some firms, including Bain and BCG, also use written case interviews or case presentations. In these, you may be given a pack of documents and create a presentation (you can learn how to prepare for that in our guide to written case interviews).

Candidate-led vs interviewer-led case interviews

The level of guidance you receive will also depend on the firm. Some interviewers ask a set sequence of questions, while others expect you to take the lead and decide where the analysis should go next.

Generally, you can expect case interviews to fall into one of two styles: candidate-led and interviewer-led.

Candidate-led (used by Bain, BCG, Oliver Wyman, and almost all other firms): In this format, interviewers give you more control over the pace of the interview. You're expected to take the initiative and lead the way to solving the problem.

Interviewer-led (used by McKinsey): In this format, interviewers tend to control the pace of the interview much more. They will have a list of questions about the case they want to go through with you, and will take you from one question to the next. If they feel you spend too much time on one question, they might interrupt you and ask the next question.

Some consultants say that candidate-led interviews are harder because you have to take charge of both solving the case and leading the discussion.

Regardless of the format, interviewers will assess the same set of skills, which we’ll cover in the next section.

For more information on interviews at specific firms, see our bespoke interview guides:

• McKinsey case interview guide
• Bain case interview guide
• BCG case interview guide
• Oliver Wyman case interview guide
• Deloitte case interview guide
• EY case interview guide
• Accenture case interview guide
• PWC Strategy& case interview guide

1.3 Case interview grading rubric 

Now, while grading criteria differ from firm to firm, case interviewers tend to assess the same five areas: 

1. Problem structuring

Interviewers assess how well you break down an ambiguous problem into clear, manageable parts. The categories in your framework should usually be mutually exclusive and collectively exhaustive (MECE), meaning they do not overlap and together cover the full problem.

2. Quantitative ability

This is not about being a human calculator. The interviewer wants to see whether you know which numbers matter, can explain your approach, and can interpret what the result means for the client.

3. Creativity

You should be able to generate creative, out-of-the-box ideas in a short period of time. Interviewers want to see range and depth rather than cookie-cutter answers you can find in online case frameworks.

4. Business judgement

At the end of the day, you won’t need an MBA to do this role, but you will need to understand the fundamentals of how a business works. This includes understanding how businesses generate revenue, manage costs, respond to customers and competitors, and assess the risks of a decision.

5. Clear communication

Explain your ideas clearly, concisely, and with confidence.

Consultants constantly present to clients and work through problems with them, so your interviewer will assess how well you structure your thoughts, respond to questions, and walk them through your reasoning.

Keep in mind that everything you do in the case interview is going to map back to these five dimensions, so you should keep them in the back of your mind throughout.

1.4 What's the difference between first- and second-round case interviews?

You may encounter case interviews during both the first and second rounds, but they can look quite different at each stage. Here are several important differences to keep in mind:

• Structure: Second-round interviews can be less structured, with fewer graphs or exhibits and more emphasis on brainstorming, creativity, and business judgement
• Difficulty: Second-round case interviews may involve more complex cases or scenarios compared to the first round. This is because candidates have already demonstrated basic problem-solving abilities in the initial round.
• Depth of analysis: Second-round interviews may require candidates to delve deeper into their analysis and recommendations, exploring various aspects of the problem in greater detail.
• Behavioural questions: First-round interviews often focus heavily on the case, while second-round interviews may include more questions about your experience, motivations, and fit with the firm's culture

There is also a difference regarding who will be interviewing you. You can expect a first-round case interview to be run by an Associate (2+ years of experience) or an Engagement Manager (4+ years of experience). In contrast, in the second round, you'll be interviewed by Partners (+10 years of experience) who are more likely to ask you tougher questions.

In theory, the firm takes into account your performance at both first- and second-round interviews when making final offer decisions. However, in practice, your performance during the second round carries more weight.

This is simply because Partners will have a stronger voice when the recruiting group discusses your application. It is therefore particularly important that you do well at your second-round interviews.

1.5 What are the different types of case interview problems?

Case interview problems used at the top consulting firms are generally one of the following:

• Profitability Cases: These are the most common type of consulting interview cases. They focus on identifying why a company's profits are declining or stagnant. Candidates need to analyze costs and revenues to pinpoint issues, such as rising expenses, falling sales, or market changes, and then recommend strategies to improve profitability.
• Market Entry Cases: These cases involve deciding whether a company should enter a new market. This includes evaluating market attractiveness, competitive landscape, and the company's ability to succeed in that market. Market sizing often plays a key role here, as candidates need to estimate the potential market size and revenue opportunities.
• Merger & Acquisition (M&A) Cases: In M&A cases, candidates assess the potential value and risks of a company acquiring or merging with another business. This includes analyzing the strategic fit, financial benefits, cultural alignment, and potential synergies or integration challenges.
• Response to Competitive Threat Cases: These cases focus on how a company should respond to a new or existing competitor threatening its market position. Candidates need to evaluate the competitive landscape, assess the company's strengths and weaknesses, and recommend strategies to counter the threat, such as changing pricing, improving products, or entering new markets.
• Pricing Cases: Pricing cases revolve around determining the optimal price for a product or service. Candidates must consider factors like cost structure, customer demand, competitor pricing, and the overall market strategy. The goal is to find a price point that maximizes profits while maintaining competitiveness.

Click here to learn about some other common types of case interviews.

Step 2: Learn a structured approach to solving cases↑

All right, so now that we know what a case interview is and how it's being assessed, let me walk you through the seven-step approach I always recommend to candidates.

Here’s an overview: 

1. Set up the situation
2. Build a framework
3. Brainstorm ideas
4. Analyse quantitative data
5. Estimate without data
6. Analyse charts and exhibits
7. Make a recommendation

To show you how each step works, we’ll use a realistic M&A case throughout this section. We’ll tackle how to approach each part and include sample dialogue to help you structure your answers.

Let’s get started. 

2.1 Set up the situation↑

The first step in any case is to understand the situation. After the interviewer has given the case prompt, you are expected to: 

1. Summarise the prompt to confirm you understood it correctly
2. Ask 2-3 clarifying questions that will help you build your framework

2.1.1 Summarise the case

As the interviewer lays out the case problem, you'll need to write down all the key points from the information they give you. Once you've got it down, summarize the problem back to the interviewer.

This has two benefits: 1) It's a great way to make sure you've properly understood the most important details, and 2) it gives you space to think of clarification questions.

You do not have to parrot the prompt word for word. The goal is to synthesize the information and then demonstrate that you understand the question.

Here’s one way to do this:

Don’t forget to take a brief PAUSE, and wait for the interviewer to confirm the details. 

2.1.2 Ask clarifying questions

There will almost always be follow-up questions worth asking. Your questions should help you define the objective, understand important constraints, or shape the framework you are about to build.

You can quickly follow up with the interviewer after you summarize the case and ask: “Hey, is that all in line with the case prompts that you presented?” 

If they say yes, you can proceed to ask the following clarifying questions:

The answers to these questions will help shape your framework and determine which areas to focus on in your analysis.

If this isNovaBev'ss first acquisition, the integration risk becomes a much, much bigger deal because they've never done this before. And if FreshSpark has already proposed an asking price, you’ll need to assess whether it’s fair and whether the deal makes financial sense for NovaBev.

2.2 Build a framework↑

After asking clarifying questions, interviewers will expect you to take 60 to 90 seconds to organise your thoughts and lay out a structured approach to solving the case. 

The kind of framework you create will depend on the type of case problem you're given, but most of the time you'll create an issue tree. You'll need to make sure that your issue tree is both MECE and 80/20 (read more about using issue trees in case interviews).

You might want to base your issue tree on one of the common case frameworks:

• Profitability
• 4Ps
• Porter's 5-forces
• 3Cs
• Market entry
• Pricing
• Merger and acquisition

These pre-existing frameworks can be a useful starting point. However, DO NOT simply copy an existing framework. Interviewers immediately spot and penalise candidates who do this because the objective of the framework question is to test your creativity and business acumen – not your ability to memorise frameworks!

After you have a solid understanding of the typical case frameworks, you should be able to tailor and build a bespoke framework applicable to the specific case prompt that you've been given by the interviewer. 

Now, for the NovaBev case, I’ll walk you through how I would approach it as a candidate using the MECE framework.

Notice that the MECE framework I used is specific to an M&A case. It covers five important areas: the market, the target, the client, synergies and risks, and alternatives. The categories do not overlap, and together they cover the key factors behind the acquisition decision.

I also told the interviewer where I wanted to start. This shows that I am driving the case rather than waiting for them to decide each next step.

Remember, your framework does not need to be complicated. It just needs to cover the right questions in a clear and logical order.

Learn how to build a strong framework for any case in our case interview framework guide.

2.3 Brainstorm ideas↑

At some point, the interviewer will probably ask an open-ended question to test your creativity. This could be anything from a mini-framework exercise to something closer to a brain teaser.

The key is to organise your ideas into clear categories. Before answering, take a moment to group your thoughts into two or three buckets.

Your answer does not need to be as detailed or formal as your initial framework. However, it should show that you understand the question and have a solid list of ideas you could share with the client.

Switching back to the M&A case, here is what this could look like in your interview:

As you’ll see, I could have simply named the three buckets and listed the ideas within each one. Instead, I clearly numbered the buckets, organised the ideas within them, and gave examples specific to the case.

This level of structure and rigour is exactly what interviewers look for. Most candidates can come up with a list of ideas, but structuring and communicating them clearly is what can help you land the job.

2.4 Analyse quantitative data↑

Next, you’ll be asked to complete a quantitative analysis using data provided by the interviewer. You’ll typically receive a set of figures and use them to calculate a relevant business metric, such as profit, market size, or return on investment.

The key here is organisation. Lay out your approach and walk the interviewer through your logic before doing any calculations. Once they confirm that your approach makes sense, you can plug in the numbers. Then, interpret the results for the client. 

Take 15 to 30 seconds to map out your calculation. I would say only around 5% of candidates are particularly good at jumping straight into the maths, so use this time wisely to structure your approach.

Calculators are typically not allowed in either in-person or virtual case interviews. That’s why you should practise doing mental maths quickly and accurately before your interview.

Luckily, there are some tricks and techniques that you can use to simplify calculations and make them easier and faster to solve in your head. We cover them in our free guide to case interview maths. 

That said, below is an example of how you can structure your answers for the NoveBev case:

2.5 Estimate without data↑

Moving on to step five, you’ll still be doing quantitative analysis, but this time you won’t be given the data. You’ll most commonly face a classic market-sizing question, where you need to develop reasonable assumptions and walk the interviewer through your calculation from scratch.

Consultants often need to provide “guesstimates” or ballpark market-size figures when speaking with clients, whether on strategy or due diligence cases. The ability to perform a quick back-of-the-envelope calculation, perhaps during or just before a client meeting, therefore has real practical value.

The same principle applies here as it does when you have data: explain your approach and assumptions → work through the calculation → interpret the result for the client.

Here’s an example of how this could play out for the NovaBev case:

To learn how to tackle market-sizing questions, see our market sizing questions guide.

2.6 Analyse charts and exhibits↑

The sixth step focuses on chart or visual analysis. The interviewer may give you a graph, table, or another exhibit and ask you to quickly extract salient details from the data and connect them back to the original case.

Here’s a 4-step approach I always recommend to candidates: 

1. Take around 30 seconds to review the title, axes, legend, units, and data
2. Share the main insights from the first visual
3. Share the main insights from the second visual, if there is one
4. Combine the findings from both visuals and explain what they mean for the case

Do not simply describe what the chart shows. You should be able to connect the data to the question you are trying to answer.

Here’s how I would apply this approach to the NovaBev case.

Imagine the interviewer gives you two charts showing the revenue growth and profit margins of NovaBev and FreshSpark over the past five years. I would start by saying:

“Would you mind if I take a moment to review these charts?”

After around 30 seconds, work through each visual separately:

Now, taking a step back and removing my candidate hat, notice how I did not simply say NovaBev’s growth is flat while FreshSpark is growing. 

Any candidate can look at a graph and identify the trend lines. What stronger candidates will do is take that information, place it in the context of the case, and use it to shape their recommendation.

Think of an interview as a funnel. You start off with these really large questions at the beginning, and you need to be iterating and iterating until, at the very end of the case, you're going to have a strongly sculpted data and evidence-backed recommendation.

2.7 Make a recommendation↑

Last, and certainly not least, we have step seven: your final recommendation. This is your opportunity to bring the case together and answer the client’s question directly.

At this stage, you should not introduce several new ideas, but simply focus on pulling together the most important findings from your analysis.

Here’s a simple framework to structure your recommendation: 

1. Give a clear recommendation
2. Provide 2-3 supporting reasons
3. Flag any risks blabla
4. Suggest the next steps

Keep your answer clear, confident, and polished. Aim to deliver it in under 90 seconds. The best candidates move into their recommendation smoothly, but you can take up to 15 seconds to organise your thoughts.

Here’s how I would close out the NovaBev case:

The recommendation should be clear, confident, and supported by the analysis you completed during the case. Do not introduce several new ideas at the end. Synthesize what you have already learned and answer the client's question directly.

Step 3: Solve practice cases↑

The best way to master the case interview process is to work through realistic examples.

Below are free practice cases and interview examples from leading consulting firms.

3.1 McKinsey case interview examples

• Beautify case interview (McKinsey website)
• Diconsa case interview (McKinsey website)
• Talbot Trucks case interview (McKinsey website)
• Shops Corporation case interview (McKinsey website)
• Conservation Forever case interview (McKinsey website)
• Loravia Education case (McKinsey website)
• Electro-Light case (McKinsey website)
• McKinsey case interview guide (by IGotAnOffer)
• McKinsey live case interview extract (by IGotAnOffer)
• Profitability case with ex-McKinsey manager (by IGotAnOffer)
• McKinsey case example (by CaseCoach) 

3.2 BCG case interview examples

• Climate case (BCG website)
• Digital strategy (BCG website)
• IT architecture strategy (BCG website)
• Chateau Boomerang written case interview (BCG website)
• BCG case interview guide (by IGotAnOffer)
• Written cases guide (by IGotAnOffer)
• BCG live case interview with notes (by IGotAnOffer)
• BCG mock case interview with ex-BCG consultant: Revenue problem case (by IGotAnOffer)

3.3 Bain case interview examples

• Milk alternative practice case (Bain channel)
• CoffeeCo practice case (Bain website)
• FashionCo practice case (Bain website)
• Associate Consultant mock interview video (Bain website)
• Case interview tips (Bain website)
• Bain case interview guide (by IGotAnOffer)
• Written cases guide (by IGotAnOffer)
• Bain live case interview extract (by IGotAnOffer)
• Consultant mock interview video (Bain website)
• Revenue case with ex-Bain manager (by IGotAnOffer)
• Digital transformation case, ex-Bain manager vs ex-Bain consultant (by IGotAnOffer)
• Classic growth case with ex-Bain consultant (by IGotAnOffer)

3.4 Deloitte case interview examples

• Engagement Strategy practice case (Deloitte website)
• Recreation Unlimited practice case (Deloitte website)
• Strategic Vision practice case (Deloitte website)

3.5 Other case interview examples

• Yale SOM consulting club - Playworks case (YouTube)
• Yale SOM consulting club - Airlines case (YouTube)
• Fully interactive mock case (by CaseBinge)

If your target firm isn't included above, or if you want even more practice cases, check out our list of 47 case interview examples. This list includes free cases for other firms like Accenture, Oliver Wyman, PWC, Roland Berger, etc. There are several more McKinsey cases there as well.

Step 4: Improve your case interview technique↑

Once you understand the process and have started working through practice cases, use the following techniques to improve your performance.

4.1 Push your analysis one step further

When you arrive at a number or conclusion throughout the case, don't just state the number or the conclusion and move on. You're going to need to react to it and contextualize it for the interview. 

For example, you could simply say that FreshSpark has 3% market share. That is accurate, but it does not tell the client much.

A stronger answer would sound like this:

"FreshSpark has around 3% of a $1.5bn market. That is encouraging because it shows the company has established product-market fit, but it is still far from the market-share ceiling. NovaBev's retail network could help it gain several additional percentage points, which would translate into meaningful revenue growth."

This extra step is what's going to take you from being a “calculator” to truly an advisor to your clients. That is what consulting firms want to see.

4.2 Bounce back

Every candidate gets stuck at some point. It may happen during the maths, a brainstorming question, or an unfamiliar part of the case.

The worst response is to freeze, ramble, or fill the silence without moving the analysis forward.

When you feel stuck, take a deep breath and do two things.

1. Summarise what you have established so far
2. Look at the problem from a new angle

Let’s say you're in the middle of the case, and your interviewer asks you to brainstorm the risks of the acquisition. You just came up with integration risk and talent retention, then your mind goes blank. 

Here’s what you could say:

“So far, I've identified integration risk, specifically the challenge of merging startup culture with a large corporate environment and the risk of losing FreshWorks’ key employees post-acquisition. Let me also consider the problem from a different angle."

This buys you a little time, but it also gives that time purpose. Even if it's not as smooth as if you had the full listing at the beginning, it puts you in an exponentially better position than if you had not leveraged this technique.

4.3 Personalise the case

Instead of using generic business language, you should be using terminology and framing that's specific to the industry and situation that you're analyzing. 

In our Nova Bev case, for example, do not refer to FreshSpark's buyers as "customers". Describe them as health-conscious energy drink consumers who read ingredient labels and are willing to pay more for organic products.

In another example, let's say you're discussing risk. Don't just say brand dilution; instead, frame it this way: “There's a risk that the wellness-focused customer who loves FreshBark because it's a small, authentic brand will feel differently when they see it sitting next to you.”

Personalizing your case can show your interviewer that you're not just running through a mechanical framework. You are actively engaging with the content, and you're able to personalize it to the client. 

Remember, you’ll work with clients from a wide range of backgrounds. Part of building credibility is showing that you can think carefully and communicate in language they understand.

4.4 Follow useful interviewer cues

99% of interviewers have good intentions. They're here to help you perform at your best. During your interviews, they will give you hints about whether you are doing well or not. 

If they try to steer you in a direction, follow them. They're trying to help you. This might sound obvious, but candidates sometimes get so stressed out that they don't pick up on the hints interviewers give them.

4.5 Do targeted drills as well as mocks

Full mock interviews help you practise the flow and pressure of a real case. However, they are not always the fastest way to fix a specific weakness. Doing targeted drills is an effective way to ensure you are improving on your blind spots.

For example, if you are consistently strong at chart clearing and brainstorming, but you tend to omit key points in your framework and often make one or two math mistakes, you need to focus on specific exercises targeting framework improvement and math accuracy.

4.6 Prepare for fit / PEI questions

The first 15 minutes of most case interviews are usually a "personal experience interview" where you'll be asked questions about your experience, motivations, and working style.

Don't make the mistake of thinking these questions aren't important, they are. 

Use our guide to answering PEI questions (written for McKinsey candidates but relevant to all) to prepare.

Step 5: Practise, practise, practise↑

The consulting job market is competitive, and firms expect candidates to show clear, structured thinking throughout the case.

The techniques in this guide can give you a strong foundation, but you need to practise applying them. Start by working through cases aloud on your own. Play both the interviewer and candidate, record your answers, and listen for places where your reasoning becomes unclear or unstructured.

Once you are comfortable with the basic flow, practise with a trusted peer. This will force you to respond to unexpected questions and explain your thinking to another person.

If you want to take your preparation one step further, I recommend working with a case interview coach. An experienced coach can give you well-calibrated questions and specific feedback on where you need to improve.

I wish you good interviewing!

Book a case mock interview with Britanny

One last thing: This article is an adapted text version of the video interview below (definitely worth a watch if you found the above useful).