Case interviews are an important part of the recruitment process for hiring management consultants. Management consultancies, including the Big 3 — McKinsey, BCG, and Bain (MBB in short) — conduct case interviews that challenge even candidates with impeccable academic records.
Investment banks and other industries use case interviews to select professionals with strategic business thinking skills. If you have been invited to attend a case interview, you can give your best through preparation and practice.
How to prepare for case interviews
What is assessed in a case interview?
At a case interview, the interviewer tries to evaluate your quantitative, qualitative, and analytical skills, critical thinking, creativity, communication skills, and understanding of business concepts. For these are the skills that you need for solving specific problems related to industry sectors, organizations, and businesses once you are hired.
Examples of case interview questions
The interview topics can be real cases handled by the firms or manufactured cases designed just for the interview. The interviewer is not looking for “the right answer,” though you may breeze your way into the next round of the hiring process if you manage to come up with it.
The interviewer is trying to find out how you approach the case, whether you ask the right questions, use structured ways of problem-solving, and can think out of the box. Do you use the data to quantify your recommendations and do you review your own solution realistically before suggesting it?
A case interview may last 30 minutes to an hour, and you may be put through half-a-dozen case interviews in a couple rounds or more, depending on the position applied for.
After an ice-breaking light banter, to find out whether you are a good fit for the organization, the interviewer will present the case question. You will be given time to study the case and can come up with questions to clarify it.
Here are some examples of case interview questions:
- Motorola is your client. The year is 1980. The company has invented the mobile phone three years ago. They want you to find out whether there will be a demand for mobile phones and the market size over the next three decades.
- Your friend runs a lemonade kiosk. Last Monday, he kept it open from 2 pm to 5 pm but sold only two cups. What should he do differently to improve business?
- Your client is a $300-million copper mining company. This year it lost $50 million. How do you turn the company around?
Different types of case interviews
Case interviews can be broadly candidate-led or interviewer-led, while some may have a few features of both types. In a candidate-led interview, the candidate structures the problem, creates the framework, notes the findings, and proposes solutions. This is the most suitable interview type for candidates applying for senior positions, as the methodology is given prominence over the quality of the solution suggested.
When the interviewer leads the interview, he/she controls specific parts of the problem. The focus is not on finding answers to the bigger problem but in solving each sub-question. Business intuition is required to do well in this type of interviews.
In a candidate-led interview, you need to define the problem clearly, identify possible root causes of the problem, hypothesize to identify the most probable root-cause using the data available, and suggest a solution.
In an interviewer-led interview, you need to tackle each question from the interviewer. The best approach is to take each question as a mini-case and categorize it under the following types:
|Math problem||How many pizzas does a barely successful pizzeria have to sell to double its profit?|
|Market-sizing||What is the market size in India for entry-level sedans?|
|Framework||What factors would you consider for solving the client’s problem?|
|Solution-finding||What steps do you think the loss-making company should take?|
|Insights||What do you learn from the company’s profit charts?|
|Value proposition||What do customers look for in sedans?|
|Business valuation||What is the company worth today?|
|Hypothesis||What could be some of the causes of the client’s problem?|
|Brainteasers||How do you know the refrigerator light goes off when you close the door?|
Business cases, estimating cases, and brainteasers require a knowledgeable approach and detailed analysis. Business cases deal with a company’s profitability and investment opportunities, estimation cases revolve around the potential profitability of a product or a market, and brainteasers require you to do some out-of-the-box thinking.
Tips to tackle the case interview
Whatever the style, you would need to keep a cool head and focus on the case. Take the case interview as a business discussion. Listen carefully, and make sure that you have understood the case by asking relevant, concise, and clear questions. Outline your approach, which would show that you are purposeful.
Watch out for feedback signs from the interviewer, such as facial expression or body language, which could tell you whether you are on the right track or not even close. Try to buy time by repeating the facts about the case, which could also suggest to the interviewer that you understand it well.
Form a hypothesis only when you are certain that you have adequate information. Ensure that your hypothesis is based on the facts given. Be pragmatic, and ask yourself whether your recommendations are realistic and can be implemented.
Don’t make wild guesses, and don’t be flustered when presented with some new information. Take structured notes that are clear and coherent, so that you can refer to them and you don’t lose sight of the case information. But be wary of concentrating too much on writing things down lest you miss some of what the interviewer is saying. Polishing your mental math skills by learning a few shortcuts before going for an interview will enable you to solve some problems quickly.
Show that you are interested in the field and the firm by asking good questions. Ask about the interviewer and his/her professional background, experience with the firm, and the work that consultants do.
Wikihow gives tips on how to do well at case interviews. It says you need to realize that the interviewer would be impressed more by your knowledge of consultancy-related topics, such as economics, rather than your math skills. Try to understand the problem thoroughly and boldly ask for any clarifications that you might want.
See how the business has responded to its problem, and identify which of its responses were effective and which were not. Suggest alternative solutions, using data and calculations, to support your ideas. Speak about the changes that you would make, for example, in strategy and management, to implement the solutions that you have suggested.
It makes sense to use a simple problem-solving structure. Communicate your answers effectively. As the interviewer is not looking for the right answer as much as your approach to the problem and thinking process, keep communicating with him/her. Summarize, so that you can go over your key points and also are able to limit them to three to avoid confusing the interviewer about your main conclusions. Conclude by emphasizing your findings and solutions to show your understanding of the case.
Take the case interview as an actual problem-solving task at your workplace with the interviewer as your colleague; relax, and make your interview a fun experience.
Apart from your problem-solving skills, interviewers also try to assess your character and knowledge. They may try to pull your leg to see whether you lose your cool easily. They may try to behave rudely to see how you tackle stress. Hold your ground and respond with equanimity.
Practice makes a winner
Doing well at a case interview is no mean feat. There should be a lot of practice — some experts suggest spending 50 hours over six weeks. Devote some time to reading business sections of newspapers to know about the markets. Also go through business publications, especially those from Bain and Co., BCG, and McKinsey, to improve your business intuition.
Master your problem-solving skills before practicing case interviews or trying out mock interviews. Watch sample case-interviews available on YouTube, uploaded by consultancy firms, interview prep companies, vloggers, and b-schools (see our post Case study method: Why and how the best b-schools use it.).
Companies also have case-interview resources online: for example, BCG and Deloitte have interactive case libraries on their websites. The more you are familiar with the various types of business situations and case frameworks, the better you will be able to assess the interview question and provide a solution.
What if you only have four or five days to prepare? Cancel everything and focus on your preparation. This means you will be preparing ten hours a day. But get enough sleep, particularly on the night before the big day. Get a friend who can give you a case interview question and play the role of the interviewer.
It helps to research the firm that is interviewing you. Find out who its clients are and gather information about the clients’ businesses. Look back at your own experience for an example to narrate, and practice telling the story. Management consultancies put up information about their interview process online, including typical case interview questions. Familiarity with their procedures improves preparation and confidence. Pick up some acronyms and terms widely used in consultancy.
Management consultants meet top executives from a number of client companies, many of whom prefer formal, traditional attire. Turning up for an interview in informal clothes may not be a good idea. A dark, plain suit is often the best choice.
Here’s McKinsey’s advice to tackle its case interviews: “Practice case studies. Prepare with a friend. Then take a nice long run, meditate, or do anything that helps you feel calm, confident, and collected. If you feel nervous, remember that [by inviting you for a case interview] we [already] think you have what it takes to join McKinsey.”
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