Case Interview Overview
So you want to a consultant, eh? If you’ve spent more than ten minutes reading about this career path, you’d likely have encountered the “case interview” by now. Let me underscore this once more for good measure: being fantastic at the case interview is tablestakes for entering the consulting industry.
Any consulting company worth its salt will not give you significant time of day until you prove that you can “crack the case” (as all the consulting industry coaching likes to call it). Sure, you need to first get invited to interviews via your resume (sadly, no special tips from me on how to get your resume to stand out - other than the regular advice on demonstrating impact and having action verbs for your bullets). Once you get to interviewing though, you’ll find the big-name companies put a heavy emphasis on casing. (The case interview is often shortened to just “the case,” as in “the case portion of the interview” if the company will also include a brief behavioral interview - like McKinsey - in their interview rounds. And yes, the verb form can be considered industry jargon, since conventionally “to case” could only refer to “covering something” or “checking out a place (before robbing it)” - whereas within the context of getting into a consulting career, it’s just “to do the case interview.”)
What is a case interview?
What is a case interview? The “case” is a “business case”: a simplified problem given to you to solve, usually framed as an ask from a client. It’s play-pretend: we’re going to pretend you’re a consultant working for our company, and that we have a client who called us up with this particular problem.
Note that it’s not the same thing as a business case where, in a corporate environment, you make a justification for why something should be done. Nor is it a business school case study, which are mostly published by Harvard (you can read more about the Harvard Business School’s “Case Method” which most MBA programs will also tout as part of their pedagogy). These case studies are long-form narratives in prose form, occasionally accompanied by exhibits, that tell the story of a particular company’s history and/or a specific problem they encountered and how they approached that problem. Not all companies come out of their situation standing as winners!
Back to this role-play situation - what’s the point?
To evaluate your problem-solving skills. (What does that even mean? What are problem-solving skills? Can anyone give me a definitive list? If they’re nebulous and context-dependent, then how on earth are they being evaluated, and why is the case interview better at sussing them out than other interview formats?)
To assess your analytical prowess. (Exact same questions as above. What?)
To simulate real-world business situations and see how you handle them. (I’m sorry, I’ve yet to meet a client who has a business problem so simplified and succinct they can describe it entirely in 30 seconds. And I’ve yet to hear of a project that goes the way a case interview does. It’s not very real-world. Even if the case is based on a “real-world” situation that happened, it’s been simplified to an essence because we don’t have time for complexities in the interview process.)
The point is to get a glimpse of how you think. The case interview is the consulting industry’s version of a job trial (alternatively known as work trials, or trial shifts, or task-based interviews). The case interview best represents what consulting work is like in its purest form; the different components of the case interview demand that you showcase the various things that consulting firms value:
professionalism
clear and concise communication
the ability to see the bigger picture
the ability to consider little details
the ability to summarize
being organized and methodical
quantitative skills (or just a sense of how to approach calculations).
The only way to assess how you think is to ask you to articulate all your thoughts. I remind all interviewees to “talk it out” or “walk me through everything.” Don’t be surprised to find that there’s some difficulty involved in the degree to which I expect you to externalize your internal dialogue! We don’t normally go through life being so explicit in our assumptions, our thinking process, the micro-decisions we make - in fact, many of the assumptions we make are decided upon so quickly, we may not even register that our brains had done any processing. (Think about unconscious biases - they’re unconscious because they are deeply embedded and happen much faster than you register; they’re biases because they’re based on a whole lot of assumptions that color the way you perceive your reality.)
There are two benefits from voicing all your thoughts. First, it helps me, the interviewer, evaluate you better. Two, it helps me redirect if you get stuck, because I’m more likely to understand where you took a wrong turn, what you missed, etc. That’s why I want to hear exactly how you think, and everything that comes to mind during the case interview.
But that’s a lie: I’m not actually interested in your stream of consciousness. I want you to filter and package your thoughts up. Make them super digestible and easy to follow, and we will both pretend that’s just how your thoughts sprung up in the first place.
Here’s an example. In your head, the sequence of words may go something like this: “Um…there’s three countries in this list…$1 billion for Country A, $8 million for Country B, that’s $3 billion for Country C, okay…so obviously Country C represents the biggest opportunity.”
When you open your mouth, I want the words to tumble out like this: “I see here that there are three countries under consideration, and the total market size for each country listed. Country C stands out to me because at $3 billion, it is the largest opportunity, three times bigger than the next candidate, Country A. That’s why Country C seems like the best choice, presuming that there aren’t any significant difficulties in entering Country C. ”
Who thinks like that in their head at the first pass? No one. The preferred statement is organized: the most significant piece of information came first (the answer), along with reasoning and some quantification (supporting evidence), followed by an explicit assumption, which both presents an opportunity for me to validate your holistic thinking and for me to smoothly introduce any plot twists.
Oftentimes the case interview is described as a problem-solving assessment. Here’s an important caveat: it’s more about how you solve the problem, and less about if you solved the problem. Whether or not you get the “right answer” (presuming there is one; some companies will give you cases that have no definitive solution) matters less than having the “right approach.” The most common question I get asked after a case is, “Did I get it right?” which is altogether the wrong question to be concerned about. Cases come with a whole lot of ambiguity, as do most consulting assignments. So, can you find your way out of the dog?
This is why the initial framework (also called your “structure”) is so important. How you draw up the framework reveals a lot about how you think. If you have the right approach, but didn’t get the right answer - it’s okay, because you still demonstrate that you have the problem-solving skills. The right approach is repeatable. An approach can be adapted to different situations. It’s as if you were dropped into the middle of a forest and asked to find your way out. Sure, you can stumble out of the forest by sheer luck, and you can still remain lost even if you apply all your compass-reading, animal-tracking, whatever else scouting skills. But because I’m using your navigation of this forest to form an opinion of how you’d navigate a dozen other forests, I’m going to be a lot less impressed that you found your way out by “turning left at every third tree my right foot brushes.”
How to prepare for the case interview
One word: practice. There is no substitute for practice. And practice only counts when you “case” with a live human being. I recommend “case swaps” - when you get together with another aspiring consultant, and take turns playing the role of the interviewer for the other person to be the interviewee. Lots of MBA Consulting Clubs have uploaded their “case books” to the internet: search, download, use. Don’t get too picky: sure, not all cases are great, some are too hard, some have mistakes, some are too detailed, some are too vague. As you go through your reps, you’ll identify your own favorites to use on others when you play the role of interviewer. But take cases from others indiscriminately: frankly, every case will give you a chance to hone and refine a different aspect of your case interview technique and style.
Playing the role of interviewer helps you discover how things actually sound - what’s clear, what’s boring, what’s godawful. At the beginning of my preparation journey, I definitely saw “giving” a case interview as the boring part - the price to pay to get someone else to give me a case and some feedback. (Sometimes the feedback wasn’t even worth it. But the practice always was.) As I expanded my practice to include many, many strangers on the internet, I started to realize that I was learning more from being the interviewer than I was just going through the same steps in my own practice. I learned much better ways of phrasing things from other people than I would have ever come up myself. I realized how incoherent one sounds when one literally “talks the interviewer through their math” (read more about doing calculations during the case here). I figured out which parts were really key to assessing the candidate in front of me - and which parts I could tune out. That’s how I came to develop my own style, preferences and confidence, and how I started to sound polished yet authentic.
None of these things could be gained through reading and working through a case on paper. Live practice case swaps or bust.
My personal case journey
I thought I couldn’t possibly get better at case interviews, and then I did. I was the only person in my MBA class that got summer internship interviews from all three MBB companies. I made it to the final rounds with both McKinsey and Bain, though I didn’t advance beyond the first round of cases with BCG. I had spent all winter break intensely trying to beef up on case practice. I was invited directly to the final round for the full-time role with McKinsey. That interview would be in September. As soon as summer break started, I went back to casing. I did at least a case a day starting mid-May until September. “Isn’t it too early?” “You could only do so much.” “You’ll get burned out and sound stale.” People who said that had no idea - there was a whole new level I unlocked through practice.
And yes, casing got fun. In fact, casing got easy. It was easier to keep practicing cases than work on my response to the Personal Experience Interview (PEI) questions McKinsey poses in their behavioral interview portion. I would actually get energized to do a case - that much of a nerd! After that, I do believe that if you don’t like doing cases, you’re not going to like working in consulting.
I should note here that the day-to-day work as a consultant nowhere resembles a case interview. Not even close. Some components of projects may resume portions of the case interview…in spirit…if you zoom out really far. You pretty much never get an exact copy of the case interview on the job. This is especially if you go into consulting out of undergrad: as an analyst at any firm you’ll probably never get to do any of the things you do in a case on your own. (But of course to get the job, you still need to get super smooth at talking and working your way through that case! Even if the job just involves you looking up profiles with a LinkedIn Recruiter subscription because your project needs soundbites from “subject matter experts.”)
Working as a consultant involves a lot more PowerPoint slides than the case interview will ever lead you to believe. (Read here for other expectations-versus-reality realizations that dawned on me about the actual job.)
On that note, there is a (somewhat rare) case interview format that does simulate the real job. Bain, for example, offers a “written case” - and this better simulates what a “consulting project deliverable” may look like. You don’t actually write much for the case, despite the name: you get a pile of slides, and you have to pick the relevant ones and distill the message. Basically, you’re making the executive summary of a whole deck. Typically the scenario may be presented as “you are prepared for a one-hour presentation but the CEO has an emergency and now only has 10 minutes.” You’ll still be evaluated on all the same things, but you’re really put on trial for how well you can digest and distill information. Oh, and if you don’t get the bigger picture, you’ve got no chance. You have to fully understand the gist of the issue before you can move on to identify the relevant slides.
Last note (phew!) - you may have heard about the airport test or the airplane test. Essentially it’s just a totally subjective evaluation of “are you an interesting enough person to talk to” especially if you’re stuck in a less-than-fantastic environment. It’s totally subjective, so you may get evaluated during the case, but probably more likely during the behavioral interview portion.