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How to Ace the Case interview

Most strategy interviews will have a case interview as part of the process. Some love case interviews and other are terrified of them. PREPARATION, however, is key!

There are many different types of questions you may get in a “case interview”. We often find that for industry roles, the case part of the interview is a small part and it may only be a market sizing exercise. This is increasingly common these days.

Other case interviews are more comprehensive and aligned with the case interviews one would expect to receive if interviewing at McKinsey, Bain or BCG. They require: 

Market Sizing


  1. How many golf balls can you fit in a Boeing 747?
  2. How many wedding dresses are sold in India every year?

With market sizing the interviewer is mostly looking for the structure and approach you took to get to the answer rather than the answer itself, but it does test your high level numerical skills too. Ideally you should be in the ball-park, with approximately 20% margin for error. If you fail to share your approach and thought process when answering the question you are unlikely to pass. Having a structured, communicative approach, asking clarifying questions and being able to identify what drivers are behind such estimation questions is essential for a useful and convincing response. 

Business Case

We find hiring managers ask business case questions that are either current and relevant to them and a likely challenge they’ll face or have faced previously. Sometimes they like to ask a question that the candidate would never expect, possibly completely outside of the sector they’re in.


  1. The CEO of a cement company wants to close one of his plants. Should he do it?
  2. A top 20 ASX-listed bank wants to lead its industry and believes improving customer experience is the best way of achieving this. How would you test this assertion? Does it have merit and if so how would you go about it?

In this type of case question, you will be assessed on your ability to ask probing and clarifying questions, providing an appropriate structure/framework, identifying and prioritising your drivers/ levers based on commercial outcomes, outlining your analytical thinking and your ability to make client-friendly pitches. Your analytical thought process, how you structure and prioritise your answer is often more important than arriving at the correct answer. 

Be guided by the interviewer as you may be going down the wrong path. They will often try to steer you back on the correct line of thinking. Listen for these subtle hints, they are NOT trying to trick you. DON’T be rigid either by ignoring their effort to help you, often they are also assessing your ability to adapt to change as a measure of both adaptability and creativity in problem solving.

Please always remember to prioritise your drivers in the most commercial way as this too can be a stumbling block for many candidates.

There are two different types of business case interview, Candidate-led and Interviewer-led.


This is not common, but it can happen. In the extreme, the interviewer rarely intervenes, and the candidate will lead the approach, from structuring the problem, drawing frameworks, asking for data, synthesising findings to proposing solutions. This format can be difficult for beginners, but it does allow you control over the case. For more advanced candidates, this can be comfortable as methodology is emphasised over results.


On the other extreme, the interviewer controls the process. He or she has the candidate work on specific parts of the overall problem and sometimes disregards the natural flow of the case. The game here is not to solve the big problem, but rather to solve each question and each mini-case perfectly. The evaluation is done on a question by question basis with each question building on the last and assessing key skills along the way. The interviewer is looking for a level of insightfulness, business intuition and commercial acumen with both quantitative and qualitative drivers required.

We find our clients use a combination of these case preferences across the board. Some candidates can be caught off guard when a client does an extreme version of the Candidate-led scenario. The trick here is to remain calm, be kind to yourself and take ownership of the process. Oftentimes it’s this leadership quality they’re looking to test over and above the actual case result i.e can you function with limited information, work your way through it while at the same time holding the gravitas required to lead others through the problem. It may also be indicative of the type of environment in which they operate.

Victor Cheng is an authority on case interview prep and we recommend anyone facing a case interview to go to his website to practice. We have found time and again that those candidates that prepare do significantly better than those who don’t. Not preparing for a case interview IS preparing to fail and will not only leave you feeling frustrated with yourself but also your recruiters too.

Here is some information on different frameworks and structures you might want to familiarise yourself with.