Case Interview Preparation

by Victor Cheng

by 

Case Interview Preparation Question:

So, over the past three years, I have likely had about three case interviews to prepare for.

I now have another interview with Monitor, but was only given one week’s notice.

Before the last two case interviews I had, I also only had a week or so, was completely new to the case interview style, and had to basically cram.

Since my last one, back in March of last year, I have not looked at the material again.

With only four days to go before my Monitor interview (which came about randomly after applying months ago), what is the best way to do case interview preparation?

Any help would be much appreciated!

My Reply:

Four days is not a lot of time, as you will be competing against people (especially anyone who follows my advice and happened to find my materials early in their recruiting process) who have been preparing for several months, and often up to a year.

If you are very serious about doing well on this interview, here is what I suggest, to maximize your chances of success in such a short period of time:

Cancel everything else on your calendar.  Aim to do ten hours of prep on this per day, add in some breaks, and basically you’re going 12 – 14 hours per day.  Make sure you get enough sleep.

If you are tired, you will not learn as quickly. If you are tired during your interview, it is hard to perform well.  So my advice is 12 -14 hours per day, assuming you have nothing else on your calendar.  And get a good night’s sleep the night before your interview.

I almost blew my McKinsey Final Round #2 (I had two final rounds) because it was in New York City, I had to fly in, and because of the time zone shift, I was unable to go to bed early… but still had to wake up really early… so I slept maybe four hours.

Of all my rounds of interviews, it was my worst — just off here and there.  But it was good enough to pass, and considering I already passed my Los Angeles final round, I think they kind of just gave me the benefit of the doubt.

So get sleep.

If you are working full time and doing this much, it is too much — cut it in half.

What follows is a day-by-day plan.

** Day 1**

If you have not already, go through the free Case Interview Secrets videos (if you have already gone through those recently, you can just go ahead and use the Day #2 activity plan as your Day #1).

This will give you the key concepts, and help you intellectually understand what you are supposed to do.

** Day 2 **

Go through Look Over My Shoulder® one time — should take you about 12 hours.  LOMS is not a “how to” program. It is designed as a practice, repetition, reinforcement program.

In this program you will see 13 different candidates in real-world environment mock interviews.

(Even though they were not real interviews, people took them very seriously, including flying across the U.S. at their own expense, just to do the one interview with me in person.)

The purpose of LOMS on this day of the plan is to see how the concepts (that seem so easy and obvious in my slides during the Case Interview Secrets videos) get complicated in a real world setting.

** Day 3 **

If you have access to a friend who can give you a case interview practice case, this is a good day to do several practice cases — ideally 1 – 3 cases.

This should take you a half day, depending on scheduling. In your downtime on this day, get a head start on the Day 4 plan, as the Day 4 plan is a very long day.

The purpose of the live case interview practice interviews is to see how many of the good habits you picked up from LOMS, and what natural tendencies you have, in terms of bad habits.

If there are five key skills to doing a case interview well, most people with sufficient preparation can get pretty good at four out of the five skills.

But, there’s usually one skill that lags behind. So the purpose of the practice interview is to get better at the four out of five skills, and to find which skill is your one problem area.

Usually for this skill, you have to “unlearn” what you instinctively want to do, and “re-learn” the right way to do it.

This is often more time consuming than not knowing anything, and learning it correctly the first time without having to unlearn the wrong way first.

It is very hard to predict which area will be your problem area.

** Day 4 **

Go through LOMS a second time (and possibly start on a third time if you finished Day 3 early). This time, instead of listening at broad level, this time listen to the cases with a deep focus on your problem area.

And as you listen to the case, rather than just listen passively, this time actively listen for what each candidates says, and every four minutes assess whether the candidate is doing it right or not.

This is very important.

(If you only listen or read the LOMS materials, you only get half the value. You have to use the LOMS by engaging with it.  That is how you get the most value out of it.)

If you think they did it wrong, pause the recording and say out loud (I know it sounds a little silly, but trust me, it is very important especially given your time frame.

You need to be very deliberate about moving conceptual knowledge into auditory skills.  You can’t just think the right way, you have to think the right way and say it the right way…).

If after hearing my assessment, you discover it did not match your assessment, then use the explanation I gave for what the candidate should have done instead, and then you say out loud what the better approach would have been.

So if in your live practice, you have a really hard time being thorough in asking for data, pay attention to how the candidates in LOMS did or did not ask for data correctly. If you have a bad habit of not using a hypothesis correctly,then focus on that.

** Day 5 **

If you were able to skip Day 1 because you did it already, then I would try to split this day — half live practice with a partner, half LOMS using the same approach as on Day 4.

If you do not have access to a practice partner who is him/herself strong enough at cases to be able to give you a case, then just go through LOMS as described in Day 4.

Also to the extent you have or anticipate interviews with other firms, you can take the approach above and everywhere it says Day 1, Day 2, etc… just change it to Week 1, Week 2, etc..

After Day 5, you basically want to alternate between LOMS using the “active” approach and live practice, depending on your time and availability of a practice partner.

Also, if you do not have access to a practice partner for live cases, then just go through LOMS as an alternative.

I believe that a balance between LOMS and live practice is the ideal combination, but a fair number of people do not have access to practice partners, so additional LOMS repetition is the recommended alternative.

Based on the success stories I get from people via email, the best practice is to go through LOMS five times in the “active” way to get an offer.

Many people are not able to do this before their first interview. So I will commonly hear, “LOMS was great, I only had X days to practice and I passed (barely).

“I got feedback from my interviewer in Round 1 that I need to work on Y skills (structuring, hypothesis, math computations, synthesis, etc…) and will focus on that in going through LOMS a few more times before next week’s Round 2.”

In four days, it’s impossible to master the case study interview process.

But, it is possible (barely) to get good enough to pass a Round 1 when your competition is the weakest (compared to the other rounds).

So keep in mind you’ll need to do additional practice prior to your subsequent rounds.

And for future reference, it would be infinitely better to have more time to prepare. If you added up all the “cramming” time you had over the last three years, and did it all before one interview, my guess is it would have substantially more impact.

Good Luck!

Additional Resources

If you found this post useful, I suggest becoming a registered member (it's free) to get access to the materials I used to pass 60 out of 61 case interviews, land 7 job offers, and end up working at McKinsey.

Members get access to 6 hours of video tutorials on case interviews, the actual frameworks I used to pass my interviews, and over 500 articles on case interviews.

To get access to these free resources, just fill out the form below:

First Name *
Email *

Note: All registrations require you to confirm your email address.
Please type your email address carefully.

facebooktwittergoogle_pluslinkedin