McKinsey Interview – Learn How to Prepare for the McKinsey Case Interview from an Ex McKinsey Consultant

The McKinsey Case Interview, called the Problem Solving Interview by the firm, is arguable the hardest challenge for candidates in their recruiting process. Among all consulting firms, it is the most feared since McKinsey eliminates a significant proportion of candidates during the case interviews.

The case plays a crucial role in the evaluation of candidates, besides the Personal Experience Interview (PEI). In fact, performing well in the case interview does not guarantee an offer. Rather candidates need to show clear and consistent spikes in performance across all interviews. That is the reason why only a minute percentage of interviewees will receive their desired offer and Forbes has ranked McKinsey as the toughest firm to interview for.

Unfortunately, I (Florian) found that the information on the McKinsey application process and specifically the case interviews is often wrong, outdated, or assumed to be the same as for every other consulting firm.

Consequently, the advice given is detrimental to your recruiting success with the firm.         

In this article, I want to shed some light on this mysterious, often-talked about, even more often misunderstood McKinsey interview by answering the following questions:

  • What is the McKinsey Problem Solving Interview?
  • What skills are assessed in a case interview?
  • What is the format of a McKinsey case?
  • What questions are typical in a McKinsey case interview?
  • How is the McKinsey case interview different from other consulting firms?
  • How should you prepare for a McKinsey interview?
Expert Article by Florian
What is the McKinsey Problem Solving Interview?
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What Are Typical Questions?
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How to Prepare for the McKinsey Interview
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What Is the McKinsey Problem Solving Interview?

At the core, the McKinsey Problem Solving Interview is a case interview as it is employed by most consulting firms to test the analytical capabilities and communication skills of applicants. The interview simulates a client situation, where you are tasked to solve a specific problem that they are facing.

However, it comes with a twist. You will have to answer a succession of several questions rather than driving the case yourself as would be the case in other consulting firms. Within the interview, which is a dialogue between you and the interviewer, you need to iteratively

  • structure problems
  • propose concrete ideas
  • gather information
  • spot insights in data tables and charts
  • solve quantitative problems
  • deliver insights, implications, and test hypotheses
  • communicate in a professional and calm manner

The case is the hardest part for most candidates since it involves a number of different skills that need to be demonstrated consistently across all questions and multiple cases in succession. Depending on the office, applicants need to go through four to six case interviews before receiving an offer.

You need to convince the interviewers about your performance in all cases.

Let’s have a brief look at the different skills and the format of the interview.

What Skills Are Assessed by McKinsey?

Broadly, there are six skills that are assessed in a case interview and that you need to demonstrate consistently.

  1. Structure: Are you able to derive a MECE (mutually exclusive, collectively exhaustive) framework, breaking a problem down into smaller problems, accurately covering all aspects of the problem?
  2. Creativity: Do you think about a problem holistically, offering broad, deep, and insightful perspectives. Are you able to come up with different angles to the problem (breadth) and draft rich descriptions that qualify why these areas are important to investigate (depth)?
  3. Analytical rigor and logical thinking: Can you link the structure to creative thinking? Are you using a hypothesis-driven approach to your problem solving, i.e. have a clear picture of where you think the solution of the case is buried most likely or where you want to go next? Do you qualify your thinking, follow your structure, tackle (likely) high-impact issues first and lead the interviewer?
  4. Mental math and basic calculus: Are you able to structure quantitative problems and comfortably perform calculations? Can you derive the correct approach to calculate the desired outcome variable? Can you plug in the numbers and perform the calculations, relying on basic pen-and-paper math, shortcuts, and mental math?
  5. Business sense and intuition: Are you able to quickly understand the business and the situation of the client? Can you swiftly interpret data, charts, exhibits, and statements made by the interview? Are you asking the right questions? Are you able to make sense of new information quickly and interpret it properly in the context of the case?
  6. Communication and maturity. Are you able to communicate like a consultant? Are you following a top-down communication approach similar to the Pyramid Principle taught by Minto? Do all of your statements add value, and do you guide the interviewer through your thinking with numbering and signposting? Are you leading the conversation or are merely getting dragged along by the interviewer? Are you confident and mature? Are you comfortable with silence while taking time to structure your thinking?

Now, these skills are assessed in a very specific interviewing format, which is not natural for most applicants and needs significant practice to become second nature.

What Is the Format of the McKinsey Case Study?

A typical McKinsey case follows the PEI in a one-hour interview session. It lasts for 25 to 30 minutes in an interviewer-led format, meaning that the interviewer takes the lead and guides you through the case. Your role as the interviewee is to answer the questions asked by the interviewer before they will move on to the next question.

That means that you should not be worried if the interviewer asks a question that goes in a different direction than what you recommended or proposed.

While it is the interviewer’s responsibility to provide hints and move you through the different questions, you should take the lead within each question and almost treat every question like a mini case within itself.  

Depending on your performance and speed, you will be asked three or more questions. Only receiving three questions is actually a positive sign since the interviewer was happy with your answers to each question. Going above three questions usually happens when the interviewer wants to dig deeper into a specific question type to see if your performance is consistent or was just an outlier.

Most candidates need more than three questions to convince the interviewer, so don’t be scared when your case gets a little bit longer and consists of more than three questions.

Some offices also offer a phone case interview as a first screening device, which follows the same structure as the in-person interview.

What questions are asked in a McKinsey interview? Let’s have a look!

What Are the Main McKinsey Interview Questions?

In a McKinsey case interview, you will have to answer three different question types – broadly speaking:

  • Structuring/ idea generation
  • Exhibit Interpretation
  • Math
McKinsey Interview Questions

case interview structure is used to break the problem you are trying to solve for the client down into smaller problems or components. It is the roadmap you establish at the beginning of the interview that will guide your problem-solving approach throughout the case. Idea generation on the other hand is a structured brainstorming exercise that should generate a variety of concrete ideas with a specific goal in mind.

For chart or data interpretation, you are tasked to find the key insights of 1-2 Powerpoint slides and relate them back to the case question and the client situation at hand. 

Case math questions have you analyze a problem mathematically before qualitatively investigating the particular reason for the numerical result or deriving specific recommendations from the outcome.

 

Structuring/Exhibit Interpretation

Now for structure and exhibit interpretation, there is no right or wrong. Some answers are better than others because they are

  • broad
  • deep
  • insightful
  • hypothesis-driven, implications-oriented, and forward-thinking
  • MECE
  • well communicated (top-down, numbered & signposted)

That being said, there is no 100% that you can reach or single correct answers. It is important that your answers display the characteristics specified above and are supported well with strong arguments.

 

Case Math

As for math questions, usually, there are answers which are objectively correct (not always 100% the same since some candidates simplify or round differently – which is ok), and others that are wrong, due to issues with the

  • calculation approach
  • calculation itself

 

Importance of the Overall Picture

Now, for the interviewer, the overall picture counts. Small mistakes or ‘just-good’ performance in one area need to be balanced by a strong performance in other areas. Bigger mistakes must be avoided at all costs (e.g., answering the wrong question, completely wrong calculation approach, several calculation errors, or taking 3x longer than needed in math).

McKinsey wants to see spikes in performance in certain areas and a good enough performance in other areas. Just performing well in all questions is not enough.

Be aware that in 99% of McKinsey cases, there is no recommendation question in the end. The case just ends with the last case question. This is something many candidates are surprised by when they get out of their McKinsey interviews since they specifically practice for this.

If you answer each case question properly, you could almost say that the recommendation is included in each individually.

Lastly, be aware that for generalist consulting roles you do not have to expect any technical interview questions and you are not expected to have any relevant domain knowledge.

 

McKinsey Case Examples

Have a look at some of our interviewer-led cases from our Case Library!

How Is the McKinsey Case Interview Different from Other Consulting Case Interviews?

McKinsey Interview difference to other firms

While there are many similarities in McKinsey interviews and interviews with other firms, McKinsey interviews are interviewer-led, while other firms employ a candidate-led format.

 

Interviewer-led vs. Candidate-led Case Interview

McKinsey, BCG, Bain, and others’ cases have certain things in common:

  • The individual elements of the cases are the same. You will have to structure problems, interpret exhibits, and work through some calculations, come up with hypotheses, recommendations, implications, next steps, etc.
  • The skills that are assessed are the same. You need to exhibit strong problem-solving skills, creativity, ability to work under pressure, top-down communication, etc.

However, there is one key difference:

  • In interviewer-led cases, you take ownership of every question and go into greater detail here, while the interviewer guides you from question to question. In the interviewee-led case, you drive the whole case to ask for the correct information to work with, analyze the problem to then deduct a recommendation in the end

In a McKinsey case, the interviewer will guide you through a series of connected questions that you need to answer, synthesize, and develop recommendations from, within each individual question. There are clear directions and a flow of questions, which you need to answer with a hypothesis-driven mindset (prioritization, implications, next steps). These are arguably easier to prepare for and to go through since the flow and types of questions will always be the same.

In a candidate-led case interview, due to the nature of your role as an investigator, it is much easier to get lost, walk down the wrong branch of the issue tree, and waste a ton of time. While the interviewers will try to influence you to move in the right direction (pay attention to their hints), it is still up to you what elements of the problem you would like to analyze first. Each answer should lead to a new question (hypothesis-driven) on your quest to find the root cause of the problem to come up with a recommendation on how to overcome it.

 

Structuring the Case

Another common misconception between McKinsey and other interviews relates to the structuring part of the case. The framework derived for McKinsey vs. a framework created for other consulting firms is usually quite different.

At the core, McKinsey wants to see creative ideas communicated in a structured manner, the more exhaustive the better.

Your goal should be to come up with a tailored and creative answer that fits the question. The framework should - broadly speaking - follow these three characteristics:

  • broad
  • deep
  • insightful / creative

At the lowest level of your structure, you need to showcase concrete ideas, qualify your answer with practical examples and more details.

While for BCG, Bain, etc. you need to present your framework relatively swiftly within 1-3 minutes, to then dive deeper into the buckets where you think the solution of the case is buried, for McKinsey, there is no single solution (as discussed above).

In a McKinsey interview, you can take up to 5-8 minutes to present your structure, your qualification, and hypotheses. This is due to the interviewer-led format that McKinsey employs. The interviewer will only ask 'what else' if you

  • haven't gone broad or deep enough
  • did not explain your ideas well enough for them to stand out (again, you have time here)

The firm wants to see exhaustive and creative approaches to specific problems, which more often than not do not fit into the classic case interview frameworks that were en vogue 10 years ago...

Again, this only applies if everything you say

  • adds value to the problem analysis
  • is MECE
  • is well qualified
  • includes a detailed discussion of your hypotheses at the end

The difference in format and way of answering a question is the reason why I recommend preparing very differently for McKinsey interviews vs. other consultancies, which brings us to the last point.

How Should I Prepare for a McKinsey Case Interview?

McKinsey Case Interview Preparation

Most candidates prepare by learning generic frameworks.

Do not learn case-specific frameworks by heart, expecting them to work for every case you will encounter. There are no specific frameworks that will always work in a McKinsey Problem Solving Interview.

It is much more important to learn the right approach that will help you tackle all types of cases. While in 2021 this applies to all consulting firms, this is even more relevant for McKinsey interviews and the interviewer-led format.

Tailored Case Frameworks

What you need to do is to study each individual question type, the associated skills in a case interview and learn how to approach it, regardless of the client situation, the context of the case, the industry, or function.

Many candidates ask if there are specific cases for specific practices (e.g., operations) and then tailor their preparation for that practice, i.e. just practicing operations cases and learning operations frameworks by heart. The reality is that you will usually face a mix of cases in a domain-relevant context as well as cases set in a completely different context from the role you are applying for.

Be aware that frameworks were applicable in the 2000 years, the era of Victor Cheng. McKinsey has long caught up on this and the cases you will get during the interviews are tailored in a way to test your creativity and ability to generate insights on the spot, not remember specific frameworks.

In fact, it will hurt you when you try to use a framework on a case that calls for a completely different approach and fail to come up with creative and concrete ideas that are relevant, tailored, and actionable. Also, it gives a false sense of security that will translate to stress once you figure out how your approach won’t work during the real interview – I have seen this way too often…

 

Math And Chart Reading

Similarly, there is no math problem or type of chart that is typical for a McKinsey interview. As with the structure, learn to deal with any math or chart problem that is thrown at you.

Your goal should be - no matter the context, industry, or function of the case - to learn how to

  • build issue trees for structure and idea generation
  • interpret charts, derive the key insights, implications and relate them back to the case
  • set-up approaches for quantitative problems, swiftly and accurately calculate with pen and paper, and interpret the results, derive implications, and relate it back to the case

That is all there is, really.

Once you have learned an approach that works from a coach that is experienced with McKinsey interviews, internalize the habits by practicing drills and live interviews with peers and your chances of belonging to the minute percentage of candidates that receive an offer will significantly increase.

Next Steps

 

McKinsey Interview Preparation Material

Now that you have reached the end of this article and have collected a lot of valuable information on how to crack the McKinsey Interview which allows you to further tackle your case interview preparation.

As Florian explained in his article, it is important to internalize the habits that are needed to ace the McKinsey interview process by practicing with peers. On PrepLounge, you have the opportunity to schedule meetings with peers and coaches at any time! Just accept a meeting on our Meeting Board or propose one yourself! Alternatively, you can browse through the vast Candidate Listing to find a suitable meeting partner according to your needs and wishes! If you feel like you need some more support during your case interview preparation, there are a lot of ex-management consultants in our Coach Listing who are happy to share their knowledge with you.  So, make sure to schedule your meetings as soon as possible!

Of course, your preparation for mathematical tasks should not be neglected! Use our Mental Math Tool to train your case interview math with respect to all basic operations. You can even compare yourself to the performance of the whole PrepLounge community. This will help you to be prepared for any calculation in your consulting interview. Lastly, make sure to practice your chart-reading skills by solving our Quizzes! The sooner you develop this useful skill, the better! 

If you still have questions after that, feel free to ask them in our Consulting Q&A. Our experienced coaches are happy to share their personal experiences and have valuable tips for you at hand!

About the Author

Profile Picture FlorianFlorian

#1 rated McKinsey Case and PEI Coach | 5 years at McKinsey | Interviewer Experience | Imbellus Expert

  • Professional Experience: Bitpanda, StrategyCase, McKinsey & Company, Kearney, Lufthansa
  • Languages: English, German
  • Location: Austria

 

Florian became the #1 McKinsey coach (based on recommendation rate) within the first month of starting on PrepLounge. With 5 years at McKinsey, he knows the recruiting process inside out. He can help you ace the case interview and the PEI exactly like McKinsey wants you to succeed. His coachees continuously receive feedback from McKinsey interviewers that they seem to be much better prepared than other candidates. Interviewing and coaching 100s of candidates, he has developed a system to tackle every McKinsey case and question type successfully, regardless of the context, industry, or functional expertise. You will learn how to think like a McKinsey consultant and not rely on pre-learned frameworks that would only hurt your performance in the real case.

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