Tips and Tricks on how to Succeed in the Case Interview
As the (modified) saying goes, there are two things you can expect for certain in life: taxes and aspiring consultants encountering a case interview during their recruiting process. The case interview is one of the most mysterious things about consulting since it’s an interview that you cannot possibly know the answer to before going in. What I hope to do in this article is to break down what exactly a “case interview” is, how you can best prepare for it, and what are the keys to succeeding during one.
What is a Case Interview?
First, let’s start by discussing the definition of a case interview, also known as a case study. In layman’s terms, the interviewer presents with you some information about a company suffering from a problem and your job is to discover the root cause of that problem and propose solutions. Caseinterview.com defines it as “a hypothetical business situation that is presented during an interview process to determine how a candidate thinks about a particular problem and how they would solve it”. But did you catch the last part of that definition, “Determine how a candidate thinks about a particular problem…”? The biggest misnomer about the case interview is that, contrary to popular belief, getting the absolutely correct answer is not the most important part as long as you can show a clear structure on how you arrived there and be able to back up your solution against rigorous questioning. Before we go too deep into talking about how to “ace the case”, let me present you with an example from Bain:
Image from Bain.com: https://www.bain.com/careers/interview-prep/case-library/fashioco-case-study/
Pretty daunting, right? As you will see in the coming paragraphs, the case interview is a lot like a muscle: the more you work at it, the stronger it gets. If you are really serious about casing, I recommend the book Case in Point by Marc P. Cosentino. Widely regarded as the bible of case interview preparation, Case in Point will serve as the foundation for your case interview abilities. I used the plural term “abilities” because there are so many skills you must refine to succeed in casing, ranging from communication to mental math. Knowing this, the question becomes: what is the most efficient way to develop your casing skillset?
Developing your Casing Skillset
First, as with all new things, you have to develop an understanding of what a case interview really is, what a good/bad interview looks like, and the various types of possible business problems involved in the case. Again, I recommend reading and heavily annotating Case in Point, but if you cannot afford to do so or prefer a quicker read then caseinterview.com has a good introductory article on the case.
Once you have a good understanding of the premise of a case, it is time to begin refining your skillset, and if you are eager to jump in and do some cases right away I would urge you to pump the brakes. While it’s enticing to dive into the deep end and case right away, it will be much more efficient to enhance your nuanced skills before combining them together during an actual case interview. Another great case interview website is preplounge, and they outline the five main criteria you will be evaluated on as problem-solving, creativity and business sense, structure, math, and communication. Let’s talk about creativity and business sense, structure, and math skills since I believe these are skills that can be refined before ever doing a “live” case.
Photo from Wallpaper Flare: https://www.wallpaperflare.com/customer-relationship-management-illustration-business-background-wallpaper-agmdi
Creativity and Business Sense
Creativity and business sense sound quite daunting, especially if you’re like me and did not major in business, but the good news is you can pick up the jargon with some practice. The way to bolster your creativity and business sense is to read walkthrough case interviews and understand what bits of business sense they used to get to the correct answer. Also, there are plenty of resources online like Victor Cheng’s case interview series that can help you understand some of the business terminologies.
The Structure of a Case
Next, we have the structure of a case, which is the most crucial criterion that your interviewer will evaluate you on. Personally, this was the skill I had the most trouble with, and that’s why I am now a firm believer in working on your structure before actually practicing cases. Structure refers to the process of developing your step-by-step game plan to unlock and solve the case; think of it like developing an essay: start with a hypothesis (thesis) that you will work to prove by exploring different topics/buckets (paragraphs). For example:
Image from StrategyCase.com
Ideally, you should read the case prompt, then ask for some time to develop a structure that you will utilize to tackle the case, and trust me, interviewers want to see you take the time to think through how you will solve the case. Once you have laid out which buckets/topics you’d like to explore, then you can walk the interviewer through your logic and begin asking questions to either prove/disprove your hypothesis. During your research on case interviews, you may come across the term “framework”, which refers to previously developed structures that can be slapped on to solve a common problem. For example, if you are dealing with profitability, the “profit framework” involves breaking out profit into revenue and costs, then looking at each separately as you can see below:
Image from IGotAnOffer
While frameworks are nice, I would strongly push you to know them, but do not apply them during a case interview unless it either fits perfectly or you really have no idea how to solve the case. To interviewers, it is more impressive if you can structure a problem on your own as this shows you think like a consultant. As for how to practice structuring in a case, just get as many reps as you can at “case starts”, which is thinking through a problem and developing a structure by only looking at the prompt, then check your structure versus the solution to see how you did.
Mental Math
Lastly, we have to develop our mental math skills. I’ll keep this section short, but I would urge you to work on it throughout the day, just bring two numbers to mind and multiply/divide them. One helpful bit of advice is to solve math efficiently by rounding numbers then backing into the answer. For example, what is 57x12? That’s daunting, but 57x10 + 57x2 seems more manageable, right? The other tip I have is to double-check your work before speaking it out loud to the interviewer as it’s easy to make a mistake when you are under pressure.
Practice, Practice, Practice
Now we have concluded our section on building your casing skillset, we can actually start practicing live cases. Try and find someone who is also trying to improve their casing ability, since when you don’t feel like casing they will push you to do it and vice versa. Plus, they will be able to understand the terminology, when to give you bits of information, and judge your performance accurately. If you don’t know anyone working towards consulting, then I would suggest asking some of your closest friends/family to help you since it’s a large time commitment if they help you with multiple case interviews. At first, you may want to explain to them what a case is, when they should give you information, and how to judge your performance, so they can best help you succeed. Some final advice would be to communicate very actively with your interviewer, tell them what is going on in your mind, walk them through your logic, and continuously ask them if they agree with the approach you are taking.
In conclusion, you can become a case interview wizard; you just have to set your mind to it. Best of luck and you got this!
Title image from BKA Content: https://www.bkacontent.com/9-steps-to-creating-a-case-study/
