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Tips for optimizing preparation for MBB

Case FIT math MBB tips
New answer on Aug 13, 2020
5 Answers
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Anonymous A asked on Sep 18, 2019

Hi All,

What would be the top 5 tips you ever got or heard on MBB preparation?

I study a lot and do my best to study smart, but I would love to hear some of the tips of the more experienced people who have been through the process.

btw. this is a great community, already learnt a bunch of stuff in here!! Just want to say big THANK YOU to all the experts helping the aspiring consultants.

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replied on Sep 18, 2019
McKinsey / ex-Interviewer at McKinsey / I will coach you to rock those interviews


Here are my 5 tips:

1) Practice mental calculation daily (percentages, decimal places, large numbers, arithmetic) – even though it's not the most important part of the interview and it's allowed to make mistakes, you need to master your numbers very comfortably. If you don't, during the interview you will start feeling nervous and will perform worse on other things. I was doing at least 30 min a day of mental arithmetic for several months (download one of the apps on your phone, there are plenty).

2) Cases, cases, cases – do as many as you can. After you gather a bit of experience of practicing with your fellow students, try to find a person who is now working or has worked in the past at the MBB's recruting and ask them to simulate an interview with you.

3) Prepare and practice personal fit interviews – they are as important as the cases. Write down your stories, practice telling them with your fellow students, or with an expert.

4) Beware of your mental state – try not to stress too much before and during the interview (I know it's easier said than done). Do sports, take care of your health, try yoga, meditation – whatever makes you less stressed. I've seen so many candidates pale as a sheet of paper during my time as an interviewer at McKinsey, all worried and jittery – as you can imagine this doesn't help your performance.

5) If you get rejected, it's not the end of the world, do prepare yourself mentally for this thought! A close friend of mine became depressed for months after being rejected at McKinsey. I think it was because she treated this as a "do or die" situation. Do not do that! There are infinite options of different careers and adventures out there, you don't need to become a strategy consultant to be happy. Just try to embrace this before going into the interview room – and you will be better prepared for both failure and success.

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Anonymous replied on Sep 19, 2019

You are more than welcome! And are doing the right thing - using the crazy amount of knowledge to get yourself prepared! :)

Onto our question: here are my top preparation tips:

  1. Practice A LOT with REAL PEOPLE, both for the case and interpersonal interviews. Practising by yourself is just not enough! Yes, it can be expensive to practice with expert coaches like myself so I suggest:
    1. practising with other applicants, like yourself. Set up 2 hours to do a case for each other. The beautify of this is you learn both by practising solving the case. And by watching someone else solve the case and giving them feedback.
    2. asking consultants and ex-consultants you know who wouldn't mind helping you practice
    3. Invest in a few sessions with an expert coach who has previously interviewed for an MBB firm and can give you very clear, pointed, feedback. The advantage of doing at least a few sessions is they can then see your improvement and help you refine further before your interview.
  2. Use PrepLounge resources - need I say more? It's great!!!
  3. Use Victor Cheng's resources - I found VC particularly useful to understand the wonderful world of consulting and in particular good habits, as well as bad habits for problem-solving: Case in Point is a very helpful resource to pinpoint key principles and his daily newsletters provide handy insights in a digestible way. Also, listen to LOMS, if you can afford it.
  4. Problem Solve real businesses situations (e.g. those you see in the FT, at work, and throughout your day-to-day) - The more you make consulting a part of your every day, the more natural it will become. I remember it actually helping with my job at the time in terms of solving problems and presenting solutions to my boss. Or if you hear something on the news, think about how you would solve the problem yourself - how would you structure it, what would you analyse, what's your hypothesis, etc.
  5. Spend time on websites of consulting firms - this is both to get a feel for the firms and to learn about the interview process. e.g. McKinsey's website has loads of tips for what they expect - a lot of people skip this and it shows!
  6. Practice your Maths (no calculators!) - from everyday things like figuring out discounts at the supermarket and calculating percentages when watching the news to more structured things like using Victor Cheng's maths practice online
  7. Have fun and ask questions! It can be quite tiring - think of it as learning to exercise a new set of muscles in your brain. But it should be fun so enjoy it! :)

Shoot me a message if I can help with anything! And all the best with your preparations!



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replied on Sep 18, 2019
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School


I recommend the following approach:

1) Start with "Case in point" book - you can download this book for free everywhere. It's not the best guide on how you should approach the cases, however, it will give you the basic understanding.

2) Start practicing cases with partners here or find them locally. !!! Find experienced partners or coaches who can provide a good feedback!!!

3) Purchase and read Viktor Cheng Book (Amazon Kindle store) and listen to LOMS (his website).

4) Start with the following cases (relevant for ATK) and apply some high-level recommendations on structuring:

  1. Market sizing - structuring from the supply or demand side. Structuring using a formula or using an issue tree
  2. Profitability - basic profitability framework. Remember about different revenue streams and product mix
  3. Market context cases (Market Entry, New product, Acquisition, etc). Always start with the big picture "market". Finish with something specific to the case (e.g. How to enter?"). Structure it as if you are defining the work streams for the real project.
  4. Operational math problem (e.g. Should we increase the speed of an elevator or just buy a second one? How should we reduce the queues? Etc.) - Structuring as a process / value chain, with inflows, operations, and outflow

Here is a good list of articles regarding the different parts of the case:

1) Start with clarifying questions:

2) Communicating while structuring. Here is a long post by me on how to communicate the structure during the case study:

3) Using hypothesis. I made a post about hypothesis here:

4) Communicating while making calculations:

  • Always tell the interviewer your approach
  • Check with the interviewer that your approach is correct
  • Come to the interviewer with some preliminary answers
  • Check your assumptions with the interviewer

5) Communicating during the analysis of graphs / tables

  • Take a minute to look at the graph. Read the graph title. Look at the graph type and define the type (pie chart, line chart, etc). Look at the legend (ask for clarifying questions if necessary). Identify whats going on on the graph. Look for: Trends, % structures. Look for unusual things - correlations, outliers,
  • Make 3-4 conclusions from the graph. Think out loud on potential hypothesis on what could be the root cause / what are the consequences
  • Prioritize the most important for your current analysis and move forward with the case

6) Communicating while having questions on creativity

  • Ask an interview for a minute to think
  • Think of several buckets of ideas (e.g. organic growth / non-organic growth / differentiation). Remember to think as big as possible
  • Narrow down to each bucket and generate as many ideas as possible
  • Present the structure (buckets) and then your ideas

7) Communicating your conclusion. You can find a good example I've posted here:

8) Communicating your FIT stories

Use the top-down approach while communicating your stories. "The Pyramid Principle" is the must-read by ex McKinsey on this topic.

I recommend using the STAR framework:

  • In Situation, you should briefly provide the context, usually in 1 or 2 sentences
  • Task usually includes 2 or 3 sentences describing the problem and your objective.
  • Then you provide a list of specific actions you took to achieve the goal. It should take 1 or 2 sentences per action (Usually 3-4 actions). Note that the interviewer can stop you any minute and ask for more details.
  • The results part should have 1 or 2 sentences describing the outcomes. This part is finalizing your story - make sure it can impress the interviewer and stay in the memory.


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replied on Sep 18, 2019
OW | HEC Paris | Helped 20+ people entering BCG, OW, ATK etc.


If you study a lot and you do your best than you already already on the right track.
Since consultants love the number three - please use it instead of 5 during interviews :) - here are my tips:

1) Know that it will be fine anyway

This mindset will help you with stress, fear etc. You are probably very smart and hardworking, so you will for sure get a great job anyway (yes you will!). Also, sometimes rejection is bc of factors beyond your control (e.g. no headcount, women quota, partners did not like your shirt etc.), so please just focus on how what you do and know it will be fine anyways.

2) Prepare through interviews with other firms

If you have not sent at least 15 applications, well go submit some more. Doing cases with peers (or mock interviews with consultants) will never give you that adreline that real life interviews do. So please make sure you arrive to your dream MBB day with at least 5+ interview sessions with other firm.

3) Behave like a consultant

This is the one thing every firm looks for: hiring consultants. There is not 1 way to do it but the below are very important:
-always talk in a structured way
-say everything with 100% confidence
-dress properly, from shoes to shirt to tie - no skimping here please

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Anonymous replied on Aug 13, 2020

Hi Anonymous!

The most important tips for your efficient preparation are:

1)Practice fast math (you should know how to work with zeroes, to multiply double-digit numbers, to use math tools and so on)

2)Work with experts, who are aware of the relevant situation and can provide good feedback.

3) Focus on the most common industries in the following priority(sorted by probability of getting a case): 1-retail and CPG; 2-airlines; 3-Telecom; 4-banking; 5-natural resources; 6-tech.

4)Read Viktor Cheng Book and use the LOMS-his website.

5) Important! Don't forget about the FIT interview part. Creating your stories requires a couple of weeks!

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Daniel gave the best answer


Content Creator
McKinsey / ex-Interviewer at McKinsey / I will coach you to rock those interviews
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