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Dear all, preplounge has been my most important tool for my interview preparations. Thanks to my extensive preparations on preplounge and approximately 70 meetings, I achieved to receive offers from McKinsey&Company, Bain&Company, Roland Berger and Monitor Deloitte. In my opinion, there is no substitute to practicing actual interviews with peers. Books can only give you theoretical background knowledge that might be useful. Cheers, Florian

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Case interview: What is that?

A case interview is a specific kind of job interview that is commonly used in consultancies. This interview type is used to assess the skill of applicants. Case interviews are well suited to evaluate a candidate’s quantitative and qualitative skills, which are necessary in consulting. A consulting case study usually contains a primary question, which can be categorized as one of three types:

  • Business cases
  • Estimating cases
  • Brain teasers

A business case evolves around estimating a company’s profitability and opportunities of investment. An estimating case, also known as market sizing case, confronts the applicant with the challenge of estimating the potential of a certain market for a specific product. A brain teaser is usually a riddle which requires logic and out-of-the-box thinking to solve it. Overall, all three case types require applicants to thoroughly analyze the problem and find a well-structured approach to solve it. The way you deal with consulting cases reflects part of your later work as a consultant. Eventually, it comes down to two questions that the case helps answering:

  • Do I trust the applicant to work independently with a client?
  • Is the applicant personally and professionally suited for intensive teamwork?

Case interview solutions

A case interview has no "correct" or "standard" answer. Instead, you might just end up exploring issues and walking down several paths. There are always multiple answers or recommendations to give in a case interview. It might also be a completely different solution from what interviewers expect. In the end, what matters is solely how you get there.

Tackling a case is similar to a work day in consulting: You meet with the consultant and both of you work on solving a client’s problem. Act as if you are already working at the firm: Pretend this is a real case and you are solving it in a face-to-face conversation with your interviewer. The questions are usually quite general in nature and cannot be solved on your own, so you’ll need to initiate a dialogue, ask questions and present ideas and hypotheses.

Case structure

Case interviews usually follow a similar framework: You’ll start off with a light conversation, involving a consultant who acts as interviewer. He will start with estimating whether you are a personal fit, followed by the actual case question. You have paper and pen available, so you should start taking notes at this point. Usually, your counterpart also collects them after the interview and uses them to judge the structuring of your method. Once you have received your question, repeat it and get clarification, to make sure you start off correctly. Ask for the objective of the case and take a moment to estimate a general approach. Afterwards, the interviewer will provide you with sufficient time to let you present your approach. The rest of the interview is intended to be a dialogue. Most of the questions have to be asked by you, in order to get closer to a solution. However, the consultant is willing to guide you through the case with his answers or by asking questions himself.

Depending on if you are aiming for an internship or a full time position, you’ll have to participate in up to six of these case interviews in two or more rounds. Each interview is set to take 30-60 minutes. However, do not rush through the case and concentrate on what the interviewer says. Usually, he provides you with important details that will help you solve the case. Try to be proactive and lead through the case in a steady pace, because you will be provided these details only for showing effort: The interviewer estimates whether you ask for the data yourself and if you focus on crucial information only.

Why practice case interviews?

Whether you aim for a career in consulting with one of the small firms or you want to work for one of the big players like McKinsey, BCG, Bain or Deloitte — case interviews prepare you for the daily reality of your future work as a consultant.

Join our case interview community today and practice case interviews with expert coaches or peers from all around the world. Prep for the various challenges that await you in the interview: Start preparing for a huge variety of brain teasers, market sizing cases and more. Exchange experiences with peers from around the world in our forum, or prep with mock-interviews. PrepLounge gives you the platform to successfully start your career in consulting.