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How to Prepare for Business Case Interview as an Analyst?

As a data analyst or data scientist, we not only need to know probabilities and statistics, Machine learning Algorithm, most importantly…

Consulting Case Study 101

How to Ace the Case Study Interview as an Analyst

The Ultimate Guide to Case Study Interview Preparation

Photo by Clem Onojeghuo on Unsplash
Photo by Clem Onojeghuo on Unsplash

As a data analyst or data scientist, we not only need to know probabilities and statistics, machine learning algorithms, coding, but most importantly we need to know how to use these techniques to solve any business problems. Most of the time, you will be given a 30–45 min interview with a single data scientist or a hiring manager in which you’ll answer a multifaceted business problem that’s likely related to the organization’s daily work.

When I first started to prepare for the Case Study interview, I didn’t know there are different types of case studies. The fastest way to be an expert in the case study is to know all the frameworks to solve different kinds of case studies. A case study interview can help the interviewers evaluate if a candidate would be a good fit for the position. Sometimes, they might even ask you a question that they actually encountered. Understanding what the interviewers are looking for can help you better prepare for your answer.

What Are They Looking For During the Interview?

📌 Logical and actionable thinking process

▶️ The interviewers care about your thought process and how you get the solution. If you are able to get the answer without any framework, the interviews might think this might just be your lucky day, and you wouldn’t be able to solve a problem next time.

📌 Adaptability

▶️ Sometimes, if you are heading in the wrong direction, the interviewers might throw you some questions to help you get back on track. If this happens during your interview, you were likely missing something they felt was important.

📌 Confidence

▶️ It’s normal to be nervous during a job interview. However, as an analyst, if you don’t believe in yourself, how can others believe in you?

📌 Clear communication

▶️ As an analyst, the ability to analyze data and interpret your results is very important. Depending on your company, some analysts do need to present their analysis to the stakeholders.

How to Always Get the Answers They’re Looking For

📣 Structure

They want to know if you can take a systematic approach to problem-solving, and that you can describe it clearly. For example, they might ask you: "This month the active user accounts have increased by xx%, can you tell us what’s going on?"

To answer this type of question, you don’t have to have an answer ready right away. What matters the most is your thought process. Don’t tell them any of your guess or assumption immediately. Answer it with a framework. Ask them questions to show that you understand the business.

📣 Comprehensiveness

They want to know if your answers cover all aspects of the problem. For example, they might give you a situation and ask you questions like "How does it look," "What is the current problem," "How can we improve," etc.

There are many ways to answer these types of questions. The key to getting the perfect answer is to be concise and provide a recommendation at the end. Let’s say the Vice-president (VP) of Marketing asks you "How does it look?" in 2 mins, you can answer it by stating what the current goal is, where we are at, how far away we are to the company’s goal, what we are planning to do next to reach the goal (suggestions), and how long it would take for us to get there.

📣 Feasibility

They want to see if your answer is practical and could realistically be implemented. Be more precise; use numbers when possible.

I’ve noticed that a lot of analysts often forget to use numbers to support or back up their points. If you want to let the manager know it’s not possible to reach specific goals based on your calculation, you should use the numbers from your analysis to prove why it. Using numbers can help your suggestions be more convincing and reliable.

📣 Audience

Sometimes, they might ask you to answer a vague question such as "How does it look," to different people (your manager, the CEO, etc.). This is similar to when a recruiter asks, "Tell me about yourself," you don’t want to get down to the nitty-gritty of the projects you’ve worked on because your recruiter may be losing interest. On the other hand, the hiring manager might expect you to talk more about your past projects.

This also applies to a case study interview. Knowing who your audience is is significant. If you are talking to the Vice-president (VP) of Sales, he or she might care more about the number of customers. On the contrary, if you are talking to VP of Marketing, he or she might not care about the number of prospects as much as the VP of Sales, and instead, they might care about how to increase response rates and conversion rates.

What Is the Perfect Framework

  1. Clarify the question
  2. Break down the question
  3. Solve each piece
  4. Consolidate them to the final result

This gives you a general idea on how to get to the perfect solution. However, for each type of case study question, we could have a different framework.

Case Study Types

There are several types of case studies. Here are the main types of case study interview questions:

  • Profit and Loss
  • Entering a new market
  • Growth and increasing sales
  • Market Size Estimation

Profit and Loss

One of the reasons why interviewers like to ask case study questions is because consultants will often need to help the clients solve a vague problem without knowing where to get started. The clients state a profit/loss problem they are facing, and they expect you to help them figure out why this happened. A typical scenario is that a company has been relatively profitable over the last few years, but suddenly their profit recently dropped. What should they do?

You can break this problem down into two parts – revenue and cost. We know that profit equals revenue minus costs. If the profit decreased and costs remain the same, then the revenue is the issue. We will need to think about how to increase revenue. If it’s the other way around, then we will need to come up with a solution to reduce costs, such as cutting production and labor cost.

Entering a New Market

Expanding into a new market can be an effective way to grow a business. Therefore, some clients might ask the consultant whether it’s a good idea to enter a new market.

Before answering yes or no, you should ask some clarifying questions to know more about the client’s company.

Here are some clarifying questions you could ask:

  • What is the company’s objective? Does it fit into our overall strategy?
  • Do we need to invest more? (distribution channels, production, new hire..)
  • What do the current and future markets look like? (Emerging? Mature? Declining)
  • Would the customer segments be different from the existing ones?
  • Who are the competitors? What size market share do they have?
  • How do their products differ from ours?
  • Are there any barriers to entry/exit?

Growth and Increasing Sales

I wish there were an ultimate way to increase sales for all companies. Unfortunately, depending on the industries and the market size, the ways to grow the company and increase sales would be different.

Here are some ways a company could try to grow its business:

⛳️ Investigate the company and the industry: we need to know if the industry is growing. If so, how much money can the company invest in expanding the company? How is the company growing relative to the industry/their competitors? Are our prices in line with our competitors? Who is our target market?

⛳️ Choose the most suitable growth strategy: once we understand more about the company and its industry, we can recommend the most suitable growth strategy accordingly. For example, if the client wants to acquire a company in a completely different industry, it might not be worth it since the target audience would be completely different.

Market Size Estimation

As an analyst, the ability to make reasonable estimates is essential. Your interviewer might ask something like: How many square feet of pizza are eaten in the United States each month?

This is a classic guesstimate question. The trick to answering this type of question is to break the question into different parts, round-up or round-down any number for easy calculation and explain why you’re estimating what you’re estimating. I decided to break the questions into 4 parts.

  1. How many people in the U.S. are pizza eaters?

Let’s assume around 2/3 of the people in the U.S are pizza eaters. There are around 320 million people in the U.S. However, instead of multiplying 2/3 to 320, we can use 300 to make calculations easier. Now we know that 200 million people in the U.S are pizza eaters.

  1. How much pizza does the average American eat in a month?

We can estimate that, on average, an American eats pizza once a month. Assuming people usually eat 3–4 slices of pizza for each meal, we can estimate the average pizza consumption per person is 4 slices. Now we need to translate pizza slices into square feet.

  1. Pizza Slices into Square Feet

If a pizza slice is 4 inches at the base and 5 inches long, the area is 10 square inches (1/2baseheight=45/2). Since, on average, a person eats 4 slices of pizza per month, the pizza area for a pizza eater per month is 40 square inches. Multiply that by 200 million people (U.S. pizza eater population), and now we get 8 billion (200 million 40) square inches. Lastly, after converting square inches into square feet (divide by 144 → round down to 100), now we get around 80 million square feet of pizza per month.

Handy Information

Knowing some handy information beforehand can help us better estimate the market size. Here are some handy information listed in the book Cracking the PM Interview:

Screenshot from Cracking the PM Interview Book
Screenshot from Cracking the PM Interview Book

Final Tips

  1. Make sure you understand the question being asked; don’t be afraid to ask questions if you need clarification of the problems. But remember! Pay attention and try to summarize what the interviewer tells you.
  2. Take time to think about the problem and create a framework. For example, you can talk about the problem statement, like what is the problem the organization is facing; then you can summarize all the recommendations you’ve come up with, and explain each recommendation.
  3. State your assumptions, but don’t make dumb assumptions such as someone is not performing well enough.
  4. Practice makes perfect! Read more case study examples and learn from them.

Resources

Here is a list of resources I use to prepare my case study interview.

Books

📚 Cracking the PM Interview: How to Land a Product Manager Job in Technology

📚 Case in Point 10: Complete Case Interview Preparation

📚 Interview Math: Over 60 Problems and Solutions for Quant Case Interview Questions

Websites

MyConsultingCoach

StellarPeers

Podcast

‎Case Interview Preparation & Management Consulting | Strategy | Critical Thinking on Apple…

YouTube

caseinterview


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