Updated: Jan 31
Case study interviews applied by McKinsey, BCG, Bain, and many other consulting firms can be tricky. Especially if your do not have a business background. However, this article is useful for every candidate from any discipline to prepare for case study interviews. While we collected how to practice for case interviews in another article, this piece of work provides a detailed view on what are the must-have skills you should improve to successfully pass every case study interview. These skills are:
The proof of the pudding is in the eating. If you have already paid attention to these skills and spent considerable time on improving them, we highly encourage you to test them with case study mock interviews. We suggest to schedule at least 3-4 interviews with professional coaches to receive in-depth feedback and further fine-tune your skills. You find one of the most affordable coaching services on the market below:
Case interviews assess your ability to analyse a business challenge, explore hypotheses, test them and develop an actionable recommendation. Critical thinking entails the rational, unbiased analysis of factual evidence. You will be given lots of redundant information as part of your prompt, or noisy datasets with irrelevant details. You must use your critical thinking skill to filter noise, understand root cause and think of alternative explanation. This can be particularly useful to interpret charts.
For example, a student of us had a Bain interview in the Netherlands and was given a chart about the increasing amount of drug the Dutch police confiscated at the port of Rotterdam since 2010. A novice candidate may think the Dutch police became more efficient in finding illegal drugs. An excellent candidate will challenge it and pose the question: what if police efficiency stagnated (or even deteriorated), and merely the volume of the smuggled drug has increased significantly. Similarly, increasing revenue streams of a company can mean that 1) the company becomes a stronger, more competitive market player; 2) the market is exponentially growing and the company is simply growing with the market; 3) the growth of the market offsets the shrinking market share of the company and it actually under performs its competitors.
Problem-solving is one of the most crucial skills to possess and constantly enhance. The skill entails the process of finding solutions to difficult or complex issues. While superior candidates will not just find a more suitable solution for the business problem prompted by the interviewer, they will also do so in a relatively short amount of time compared to their novice counterparts.The business problem can come up in various forms. One thing is certain: it will be related to the office you are applying to. Therefore, it is worth having a research on the biggest industries and areas of expertise of your target country / region. Some sample problems you may face:
How can Tesla increase its profitability?
What could IKEA build a more stress-resilient global supply chain?
How should Johnson & Johnson structure its R&D pipeline to maintain its competitiveness?
As a consultant you will use software to build complex models and perform calculations. However, it would not be efficient to use a computer program to asses your numeric capabilities during an interview. Instead, you will need to perform mental math to calculate change to customer base, NPV, profit margins etc. What mental math entails:
You are not allowed to use a calculator during the interview
You need to perform basic calculations (add, subtract, multiply, divide numbers)
You will face decimals, negatives, integer power of numbers
Normally, you do not need to be precise, +- 15% is acceptable. We suggest to clarify this with the interviewer, as they rarely expect you to round to the nearest tenth
A serious mistake will result in an immediate rejection (missing a 0, or not knowing a formula)
Prioritization can come up two ways during case study interviews. First, some consulting firms (based on our experience mostly Deloitte and Bain) tend to give you tremendous amount of information. This can be either in the form of long prompts with (oftentimes irrelevant) details, or extremely crowded charts and appendices. Interviewees are expected to prioritize the information and have a low-level look at data points which are the most relevant to the business problem at hand.
Second, prioritization can be useful to avoid "boiling the ocean". Usually 20% of the root cause accounts for 80% of the solution. An excellent candidate will establish focus points and develop a structurally solid recommendation. For example, declining profitability (e.g. -20M EUR) can be the result of declining revenues (-4M EUR) and inclining costs (16M). While a novice interviewee will concentrate on improving both sides of the equation, an outstanding candidate will ask for additional information about cost drivers and will concentrate on normalizing cost levels.
Business acumen - in short - reflects your business sense. By testing your business acumen, interviewers evaluate if you really are a good consultant material. Business acumen is keenness and quickness in understanding how a company works, how it generates money, and how strategies and decisions influence financial and operational results. Superior business acumen means you are able to understand a business and its situation quickly, and can recommend actionable solutions for its challenge at hand. Although interviewers cannot expect you, a graduate hire, to be an expert of every industry, they do demand business sense and high-level idea of how different businesses operate.
Creativity is oftentimes considered to be an important skill for artists only, but in fact, it is a must-have for consultants as well. Creativity enables you to use your imagination and come up with original ideas and invent unique solutions. Although you are not expected to produce the most innovative ideas and think about flying horses to tackle a business challenge, interviewers will demand an out-of-the-box thinking. A McKinsey, BCG or Bain interview will surely have case study that you cannot solve by using conventional frameworks (such as the one on business situation, or profitability). Creativity helps you to draw an unorthodox issue tree which covers all aspects of the prompted challenge. Furthermore, it will allow you to have a high-quality brainstorming, especially if you need to do so on the fly.
Communication is one of the most important skills assessed during a McKinsey, BCG or Bain interview. As consulting require interactions with both clients and other consultants, it is inevitable to develop superior skills to express ideas, information with people, or give instructions. Candidates are expected not just to organize their way of thinking on a case study interview, but also to professionally engage with the interviewer.
In our experience, interviewers expect two things from interviewees:
Structure your thoughts: whenever you break down a business challenge, create strategy, or present your recommendation to clients, you will need to organize your thoughts so your audience will be able to follow at ease and digest huge amount of information
Be concise and avoid yada yada: in all cases, consultants work with senior stakeholders, who have insights to support their strategy creation process, or possess the power to push and implement the recommended strategy. As the availability of these people is scarce, you must be concise while you are communicating with them. Interviewers will assess if your communication is to the point and they can trust you with contacting clients without supervision in the future.