Is practicing cases really necessary to acing the case interview and landing an offer at a top firm?
How many cases should I practice and what is the best way to practice that helps me improve the most?
To answer the questions above, take a look at the following logic diagram.
First, What are these skills that are required to pass the case interview?
In any type of interview, in order to land an offer, you need to convince the interviewer of your strong technical abilities that cater to the job (hard skills) as well as your ability to communicate and work effectively within a team (soft skills).
Some positions only require a strong technical skill and have a loose requirement on communication. For example, software engineering positions at Google or Facebook host pure technical interviews where the candidates have to write codes or algorithms to solve a computer-related issue. In many of the instances, the candidate walks in the interview room, is immediately given the technical problem, and can pass the interview by writing the correct algorithms without the need to talk much to the interviewer. Many friends of ours at Stanford told me tales of passing these technical interviews and landing offers without talking to the interviewer at all.
However, this is not the case in case interviews. To pass a case interview, you need to show both your hard skills and your soft skills. Your hard skills involve A. logical and structured thinking, B. business intuition and creativity and C. mental math skills that resemble that of a good consultant. Your soft skills involve the ability to communicate smoothly and hold conversation with the interviewer as if communicating with the manager in your internal team or the client.
Second, Does practice improve these skills?
Yes. Yes. And Yes! Over the years, we have interviewed many candidates from many schools. What we have found out is that the candidates who end up getting offers from top consulting firms are the ones who have had considerable practice going into an actual case interview. Some nailed an offer having practiced over 50 cases, other needing only around 10. But we have never encountered a candidate landing an offer without any practice.
The reasoning behind the need for practice is that you need to master the hard and soft skills I mentioned before to pass the case, but you will not master these skills without practice. To prove this point, let’s take a look at how practice can improve the three core aspects of your hard skill.
Structured Thinking
In order to present structure in your thinking and case solving, you need to understand what structures are needed for different types of cases. To solve a general business problem, a good structure you can use is the MCCCP, or market, customers, company, competitor and product. To help a corporation grow in size and revenue, a good structure is organic growth (grow volume or increase price) + inorganic growth (merger, acquisition, partnerships). To reduce cost, a good structure is to reduce fixed and variable costs. These are just a few examples of good structures to present in your thinking. If you do not practice cases, you will not know of these structures. Even if you read about these structures in books, without significant practice, you will not be able to apply them effectively and at ease during an actual case interview.
We recently interviewed many candidates on a business case, and recorded the response of the candidates. Below are the responses of two candidates, one with practice and the other without, and their responses proved just our point.
Question: Your client owns a hostel in Hawaii that hosts international travelers around the world. Your client rents the land, and operates the hostel that stands atop that land. You can think of a hostel as a hotel but a lot cheaper and caters to young travelers. The client has now asked you: How do I decrease my costs of operating the hostel?
Candidate A (didn’t do much practice):
- You can negotiate rent with the landlord that owns the land and decrease the rent cost.
- You can hire cheaper cleaning personnel that cleans the bedsheets and the rooms that travelers stay in.
- You can hire cheaper staff that operates and maintains the hostel year-round.
- You can purchase cheaper equipment and utilities(wifi, electricity, etc.)
Candidate B (practiced around 15 mock cases and subscribed to our “Ace The Case” program):
I want to look at the possibilities of reducing our costs, and I want to bucket our costs into two categories, fixed cost that occur whether we have customers or not, and variable cost that occur only when we have customers.
To reduce our fixed costs:
- Rent: You can negotiate rent with the landlord that owns the land and decrease the rent cost.
- Labor: You can hire cheaper staff that operates and maintains the hostel year-round.
- Equipment: You can purchase cheaper equipment and utilities(wifi, electricity, etc.)
To reduce our variable costs:
- Daily cleaning: You can hire cheaper cleaning personnel that cleans the bedsheets and the rooms that travelers stay in.
Notice how candidate B answered the same points as candidate A, but showed clearer structure in his thinking, having practiced mock cases and subscribed to our “Ace The Case” program.
Business Intuition
Case interviews involve many different question types and industies
Question Types
Industries
In order to acquire business intuition and creativity, a candidate must first have seen many different question types and industries to be able to exhibit intuition on something new. There is very little room for creativity if the candidate has no experience at all in case practices.
Steve jobs on creativity:
Creativity is just connecting things. When you ask creative people how they did something, they feel a little guilty because they didn’t really do it, they just saw something. It seemed obvious to them after a while. That’s because they were able to connect experiences they’ve had and synthesize new things
Case Prep Master on creativity:
Mastering cases is just connecting things. When you ask offerees how they nailed the case, they feel a little guilty because they didn’t really do it, they just applied what they’ve done in practice cases. It seemed obvious to them after a while. That’s because they were able to connect case practices they’ve had and synthesize new ways to ace the case.
Mental Math
Pretty intuitive here why you need a ton of practice to improve your mental math capabilities. Let’s make this simple, grab your smartphone and set up a timer, if you are able to solve this following list of math questions under 60 seconds, your mental math is at a level ready for case interviews. Otherwise, start practicing. Our founder was able to answer these questions in 44 seconds.
- 14 squared
- 34 divided by 6
- 1 USD = 0.84 Euro, how many USD is 100 Euros?
- 1.03 to the 48th power
- If your investment portfolio grows 7% annually and compounds year by year, about how many years will your portfolio double
- 1+2+3+…+99+100 = ?
Third, How do I practice in the right way? How many cases do I need to practice?
A picture shows a thousand words, and the picture above shows the importance of practicing a lot of cases to improve mastery of the case interview, especially when you first do case practices
When you first begin practicing case interviews, focus on two keys, practice with different people and different case types.
One, practice with different people, and best with people that have experience. Everyone has insights on how to solve the case and will give you his feedback on best practices, everyone has a gem that you want to collect. However, you will only get one gem if you collect from one case buddy. Only when you practice cases with different people can you learn from the best of everybody. Also, if there are case partners who have experience or have an offer from a top consulting firm, grab onto them, never let go and practice as many cases with them as possible.
Two, practice different types of cases, especially across different question types (refer to the different question types in the previous section). With the overwhelming number of people who are trying to get into consulting, top firms are no longer giving simple profitability cases. Instead, they are using increasingly innovative question types to select candidates. So be prepared for all kinds of question types, from revenue growth to M&A, so nothing will surprise when you are in the actual interview. It is much more important to practice different question types than to practice different industries, because the structure and procedure is often the same for a particular question type, regardless of the industry that the case is in.
After you have done a decent number of cases, say between 10-20 cases depending on your learning curve, the marginal utility of each additional case practice will start to diminish. At this point, you probably have some experience with case interviews but are still far away from a mastery level that will get you an offer. This is when you need to focus on practicing the right way, following the right guidance from experts to perfect your case-solving skills and make the most out of every additional mock case.
To find out how to practice correctly, read the insights on case prep here.
I have done mock cases, but am I practicing correct?
Ace The Case Program
Ace The Case program offers 9 live case interview videos with actual candidates of varying case interview experiences. During each of these live cases, we provide comments on the candidate’s strength or mistakes. With this program, you will master all 100+ tricks on how to “Ace The Case” and learn the secrets of why certain candidates receive final offers from top consulting firms.