BCG 1st round interview - only 3 weeks left - got stuck on practice

BCG Case Interview First Round Practice cases
New answer on Jun 05, 2020
3 Answers
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Anonymous A asked on Dec 02, 2018

Hello guys,

I don't progress with my preparation in the pace I planned and I feel like I got panic and don't know how to move forward.. This is a problem as I have my first round case-interview scheduled just before Christmas, which means I have less than 3 weeks left..

I've just finished the theory part, which means I read Victor Cheng book, I studied the method of solving a case IN THEORY (identifying problems -> structure building without force fitting frameworks -> analyzing the problem (hypothesis, test, iterate) -> recommendation) and read plenty of articles about the business scenarios and background knowledge commonly occurring and needed in case interviews (porter, 4p, valuation, accounting, pricing, guesstimation, segmentation, competitive interaction, etc.)

After that point I planned to start proceeding with LOMS and start practicing cases on my own but I feel like I'm not doing it in an efficient way.

When I tried to solve cases on my own I didn't know how to start, what kind of information I should ask for, I felt like just making a laundry question list and fishing in topics like company, product, competition, customer, cost structure, etc. There is no recommended structure or solution attached.

When I was listening to LOMS I felt like "okay, this is fine but what conclusion should I get?" I understand the logic and the dependencies between the elements mentioned but I don't feel that I can use this knowledge in practice somehow.

I bought a coaching session with an ex-MBB consultant and I was totally stuck and the mock case didn't go well at all..

My concrete questions are the following:

  • Should I reschedule my first-round interview to January? (I have 4 hours/day to practice on average)
  • LOMS: How do you suggest proceeding with it? Listening the cases once or several times? Only listening the records or pausing it when the candidate arrives to the key parts of case solving and take notes? (choose what question to ask/provide recommendation/testing hypothesis, etc) Or listening the case firstly without any stop then listen again and take notes? What is the most efficient way to use this very important material. (this is around 20 hours records, so this is definetely a key question..)
  • Practicing cases: the main question when to start it? After or during the time I'm listening to LOMS? After I start which is the most efficient order? 1. Cases on my own 2. Cases with my peers 3. Cases with coaches ?
  • Coaching session: I bought 5 coaching sessions package at one of the consulting prep sites and I plan to get more if needed.. How should I use it and when? Only use it for mock interview sessions after I can solve cases on my own/I practiced with peers or should I start it right now and ask for help me structuring a problem in practice? I feel like the first session with a coach was not efficient as I wasn't prepared enough to solving a case on my own so I might need another insights from him/her..

I have the aforementioned 'assets' (LOMS, coaching session package and case library) and I have 3 weeks. What do you suggest, how should I continue my preparation?

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replied on Dec 03, 2018
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School


  1. Please reschedule. It's quite easy and there is no penalty for that. To be honest I don't understand why so many candidates hesitate to reschedule and go to the interviews unprepared instead.
  2. Listening to LOMS / doing cases on your own doesn't count at all. You should do the cases with other partners (Ideally experienced partners or coaches).
  3. Re coaches - everyone has a different approach. I have a program that you can find in my profile. It gives decent results in a short period of time.

In general I recommend the following approach:

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). I recommend to reread the book and listen to LOMS every 15 cases. Every time, having more experience, you’ll be finding something new.

4) Practice fast math

  • Learn how to multiply double digit numbers (
  • Learn the division table up to 1/11 (i.e. 5/6 = 83.3)
  • Learn how to work with zeros (Hint: 4000000 = 4*10ˆ6)
  • Use math tools (Mimir math for iOS), Math tool on Viktor Cheng website to practice

5) Below you can find a list of the most common case types and some high-level recommendations on structuring:

  • Market sizing - structuring from the supply or demand side. Structuring using a formula or using an issue tree
  • Profitability - basic profitability framework. Remember about different revenue streams and product mix
  • 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.
  • 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 outflows
  • Cost cutting - I provided the recommendations on structuring it here:
  • Valuation - Purely financial structure with cash flows, growth rate, WACC / hurdle rate, etc.
  • Synergies - revenue synergies (price, qty, mix) and cost synergies (value chain).
  • Social / economics cases (e.g. How to improve the quality of life in the city? How to increase the revenues of the museum?) - huge variability. Practice 3-5 social cases before the interview

6) Also, I would try to 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

7) ! Important: don't forget about the FIT interview part. Crafting you stories and backups stories will require a couple of weeks!


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 answering 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 Dec 02, 2018
Ex-MBB, Experienced Hire; I will teach you not only the how, but also the why of case interviews

First, see if the company will postpone. Worth a shot, they always try to accommodate when possible.

Beyond this, the fastest way to prepare is to use a coach (i am one of the PrepLounge coaches so obviously partial to this solution, but i truly believe we offer significant value - we wouldnt do it otherwise, we all have much better ways to make money) get actionable feedback, then practice with other candidates and apply it. Then do at least a second case with a coach in the last week, for course correction and last minute tweaks. Nothing can replace practice.

Consulting is very well compensated, and a huge career accelerator - it is worth it, but you need to also want it. If you do... put out all the stops and get prepared properly. There is no "I dont have time" excuse. Good luck

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Anonymous replied on Jun 05, 2020

Dear A,

Of course, you can reschedule it. And of course practice as much as you can. And once you feel you are not improving anymore, I would recommend you to start with expert coach for structured feedback and polishing your own performance.

Good luck,

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Vlad gave the best answer


McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
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