Job Hunting in Japan: What are Case Interviews (ケース面接) and Fermi Estimation (フェルミ推定)? – How to Prepare for Interviews with Consulting Firms, Investment Banks, and Trading Companies –

What are Case Interview (ケース面接) and Fermi Estimation (フェルミ推定)?

Case Interview (ケース面接) and Fermi Estimation (フェルミ推定) are one of the application rounds in specific industries such as consulting firms, investment banks, and general trading companies. Especially at consulting firms, these are considered the essential steps, so thorough preparation is needed!

Case Interview (ケース面接)

The interviewer gives you a question regarding a business situation. You are asked to come up with a logical business solution in the allocated time. 

Sample questions:

1. How do we increase the revenue at Starbucks?
2. How do we decrease the amount of trash?

Fermi Estimation (フェルミ推定)

In Fermi Estimation, you are asked to estimate the values that would require extensive analysis, survey, and experimentations to determine exactly. You will use quick and simple calculations and rough generalizations to estimate the values during a specified time. 

Sample questions:

1. How many bags are there in Japan?
2. What is the market size of the bicycle industry in Japan?

What are they evaluating you on?

Through Case Interviews and Fermi Estimation, the interviewers test how you think and solve a given problem. They evaluate you on thought process and constructive thinking skills.

How are these interviews conducted?

There is no standard structure for Case Interviews and Fermi Estimation, so it varies depending on the company. At a consulting firm, the interviewers give you a problem and about 10 minutes to come up with a solution. Then, you present your solution to them. At international strategy consulting firms, this is done through a conversation with the interviewer. 

If you are looking to apply for consulting firms, you need to research the previous case interview questions early on. It’s important to have plenty of time to get information, get used to the problems, and practice your response.

Preparation

For Input

Study using textbooks

• Basic solutions for Case Interview: 東大ケーススタディ研究会 編著 「東大生が書いた　問題を解く力を鍛えるケース問題ノート」
This is the most popular choice for students applying for the consulting industry. It offers the basic solution and thought process needed for case interview questions, and has plenty of practical sample questions.

•Basic solutions for Fermi Estimation: 東大ケーススタディ研究会編著「現役東大生が書いた　地頭を鍛えるフェルミ推定ノート
This book explains how to solve Fermi Estimation questions in 6 patterns and 5 steps. It has plenty of practical sample questions for practice.

• If you want to learn more about the thought process needed to solve them: 内田 和成 編著 「論点思考」
This does not explain how to solve specific case interview solutions like the first book, but it teaches you the thought and solution process for the most typical questions asked at case interviews with many example questions.

Attend webinars hosted by career websites

Attend paid or free seminars

• The popular paid seminar among students is the one by Liiga Consultant Bootcamp. Access from here: https://liiga.me/events
• The popular free seminar is the one hosted by BizReach Campus. To attend, you need to register at BizReach Campus website beforehand. Access from here: https://br-campus.jp/

For Output

Create sample questions and practice

Ask friends and senpais to do a practice interview

Ask actual consultants to practice with you during OBOG Visit

To know more about OBOG visit, click here for the article!

Key Point: In the beginning, don’t time yourself. Take your time and think through the problem. Once you get used to the structure, you can start timing yourself to practice solving them faster.