How to prepare for a case study?

Case Interview Interview McKinsey

Hi everyone, I have to prepare for McKinsey case interview. Today I had my first interview and I have never done a case study before and I want to ask you, from where should I start preparing? What is your recommendation?
Thank you for your answers.

am 12. Jun 2021
Letzte Aktivität
am 12. Jun 2021
Letzte Aktivität

Übersicht der Antworten

  • Upvotes
  • Datum aufsteigend
  • Datum absteigend
Beste Antwort

Oh no! I'm so sorry Andjela, but if you had/have your first first interview today and you've never studied casing before, there's no way you pass :/

That said, learn from this experience and prepare better next time. Here are my key tips:

1) An initial planning session with a coach: 1 hour with a coach now will have a productivity multiplier effect on all your efforts moving forward. They will figure out what materials are best for you, guide you towards the best ways to learn, and come up with a preparation plan with you.

2) Leverage free resources first: PrepLounge Q&A and case library, Poets and Quants, SpencerTom, Google, etc.). Leverage these options, read-up, and build that casingknowledge

Importantly, read The Economist, the Financial Times, McKinsey Insights, and BCG Insights daily to build up your business knowledge.

3) Case with other PrepLoungers: Casing with other PrepLoungers is free. Not only do you get to practice casing, but you get direct feedback. Additionally, you learn a lot just from casing others. Finally, from other PrepLoungers you'll learn which materials/coaches are helpful.

War diese Antwort hilfreich? 21
Anonym A am 8. Jun 2021
Meant first practice interview (on preplounge)
Dear Ian, Thank you for your answer, i find it very helpful. The thing is, they contacted me so I didn't have enough time to prepare myself. My interviewer tell me about this site, so I can prepare.
Ah! I see what you mean now! Ok, so what is your timeline? If you have 4+ weeks you can likely do it yourself if you work hard, by reading materials here, practicing with others etc. If, however, you have less than around 4 weeks, you need a crash course and coaching help. There's just no other way to learn all of that content so quickly!
They didn't set the date yet. I really hope that I'll have minimum 3 weeks.
I hope so! You'll want to dedicate as much time as possible to get ready. Good luck!

Hi Andjela, feel free to contact me about this topic :)
Best regards

War diese Antwort hilfreich? 7
Dear Marco-Alexander, thank you for your response. I contacted you in a message.

Hi Andjela,

I helped several candidates to land offers from McKinsey, this is what I normally recommend to prepare (you may have already covered some of the points):

  1. Define a calendar for your preparation. Identify how many hours you have before the interview and allocate a time slot for preparation in your calendar for each day, working on the points below. Many people need 100+ hours to be ready before the interview so you can keep that as a benchmark.
  2. Read Case In Point or Case Interview Secrets for a general understanding of what a consulting interview is. Don’t focus on the structures proposed in the books, as they are not good enough nowadays.
  3. Start reading good MBA Consulting Handbooks – you can find several for free online (Insead is a good one to start). Read the cases and try to apply your structure to solve them. Whenever you see there is something missing, upgrade your structure with the new insides. Try to read at least a new case per day – in this way you will absorb better the information with constant learning.
  4. After the first 5-10 cases in books/handbooks and basic theory, start to practice live. PrepLounge can be helpful to connect with other candidates for that. There is a relevant part of the interview score that is based on your communication, which you cannot practice at all if you read cases only. Keep track of your mistakes and see if you repeat them. If so, try to identify the source of the mistake (feedback of experienced partners would be particularly useful for this). Be sure to focus on both the PEI and the case part. The latter should also cover math and graph analysis.
  5. Before the interviews, be sure to prepare your questions for the interviewer – great way to show you prepared in advance and to connect with the interviewer for a good final impression.

If you want to spend few hours only instead of 100+ and cover everything mentioned above, I developed a program precisely for that. 

Plus, I can share with you real questions asked at McKinsey in your target office (I have a db with 700+ MBB questions you won't find anywhere else - you can check on my profile if I cover your particular office).

You can click on the following link to learn more:

Please feel free to PM me if you need more information.



War diese Antwort hilfreich? 1
Dear Francesco, thank you for your response. I'll text you.

Hello Andjela!
First of all you need to know what actually the application process looks like:
* Resume and cover letter
* McKinsey Problem Solving Test (PST)
* First round of interviews
* Second round of interview
* You get an offer!

But the most important are:
 Case interview questions
Personal Experience Interview questions (PEI)

There are some tips for you: 
It’s almost impossible to get an offer at McKinsey if you are not quick and confident in mental maths. You should spend time upfront brushing up your calculation skills. 
The second one you’ll have to crack between 4 and 8 case interviews before getting an offer at McKinsey. The best way to achieve that is to always use the same step-by-step approach.  And las but not least practice cases with ex-interviewers. Finally, you can only go so far by training by yourself.   
If you follow this approach and work 30h+ you’ve got pretty good chances of getting an offer. 

Good luck!

War diese Antwort hilfreich? 0

Hi Andjela,
there are 2 aspects of the application process you have to focus on:

  • Personal Experience Interview: fit and CV questions to assess your personal impact, leadership skills, and entrepreneurial spirit. You should prepare impactful stories about your experiences that cover these 3 main pillars.
  • Case Interview: typical business case to evaluate your structure in approaching problems, problem-solving skills, and business sense. This is the most time-demanding aspect to work on. I recommend reading Cosentino's Case in point to fix the theory. Then, what will be really important is practicing mock cases with other candidates here on Preplounge.

I have supported hundreds of candidates in achieving multiple offers from consulting firms. Feel free to text me to know my approach.

Hope it helps,

War diese Antwort hilfreich? 0
Dear Antonello, thank you for your response. I'll text you.

Hey there,

The McKinsey interview consists of a case and the PEI. Let's look at both:

Case Interview

In the McKinsey case interview you will have to answer three different questions types - broadly speaking:

  • Structuring
  • Exhibit Interpretation
  • Math

Now for Structure and Exhibit Interpretation, there is no right or wrong answer. Some answers are better than others because they are

  • deep
  • broad
  • insightful
  • hypothesis-driven
  • follow a strong communication (MECE, top-down, signposted)

That being said, there is no 100% that you can reach or the one-and-only solution/ answer. It is important that your answers display the characteristics specified above and supported well with arguments.

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

  • calculation approach
  • calculation itself

How can you prepare for that:

1. Given your timeline, get a coach with McKinsey experience to

  • objectively evaluate your readiness
  • tailor a short-term prep plan based on elevating the strengths and getting the weaknesses to an acceptable level
  • actually learn how a McKinsey case works

2. Practice with other candidates and perform structure, math, chart drills given to you as 'homework' from the coach

As for the PEI:

1. Learn about the PEI dimensions

Below are the three dimensions plus some ideas on what to include:

a. Entrepreneurial Drive

  • Set a goal for yourself and pursue it relentlessly against all odd
  • The focus here should be on overcoming obstacles, showing ambition and dedication as well as ingenuity

b. Personal Impact

  • Persuade a group or individual to adopt a certain idea or plan of yours
  • The focus should really be on the influencing tactics you used to reach your desired outcome

c. Inclusive leadership

  • Show that you can manage a diverse team, leading it to a successful outcome
  • The focus here should be on all traits that make a great leader (e.g., inclusiveness, mentor, mediator, go-to person, people person,...)

2. Select the right stories with the right content

When it comes to the selection of your McKinsey PEI stories, you need to think about three dimensions in the following order:

a. Fit with the actual dimension that is asked. The stories need to fit the criteria set out by McKinsey to match with Entrepreneurial Drive, Leadership, and Personal Impact. For content ideas see above.

b. Diversity of experience. Your stories should be from different walks of life, e.g., jobs or careers, universities, extracurriculars, etc. Don’t take all stories from one experience.

c. Recency. In general, the more recent the better. Unless you interview for an experienced hire or more senior position, your stories should not date back more than 2-3 years.

Make sure that

  • you draft two stories each to always have a backup story in case the interviewer rejects the first story
  • you are aware that the interviewer might interrupt you a lot to ask detailed questions, which means your stories need to go very deep as you should be ready to answer very focused questions such as ''what did you say at that moment?'', ''How did he react'', etc.
  • create catchy headlines for each story that already convey the main message
  • you create content for each story to be able to talk freely for around 10 minutes

3. Learn how to communicate them most effectively

Communication is key in the interview. Speak like a consultant, follow a logical, top-down structure, and make sure to

  • focus on yourself and your own role all the time
  • keep the context brief and really focus on your own actions (context 2 minutes, your actions 8 minutes)

I have developed a framework specifically for the effective communication of McKinsey PEI, the SCORE framework. Reach out if you want to know more about it.

4. Shortcut get it right quickly: Book a session with a coach that knows these dimensions in and out to make sure that

  • a. they contain the right content
  • b. they are communicated in the most McKinsey-like way
  • c. you can anticipate and prepare for the detailed drill-down questions the interviewers will ask

No story I worked on with my candidates has ever been rejected. Reach out if you need help!


War diese Antwort hilfreich? 0
Dear Florian, thank you for your response. It's very helpful.
You are very welcome! :-)


Content Creator
BCG | 100% personal interview success rate (8/8) and 95% candidate success rate | Personalized interview prep
Q&A Upvotes
63 Bewertungen