Case Cracking: It’s not just for Consultants Anymore

Aspiring consultants aren’t the only ones facing questions such as “How many iPhones were sold in France in 2019?” during their job interviews. Analytical or case-interview questions are muscling their way into the hiring process for everything from marketing to tech, and job seekers need to be ready.

Thankfully, all it takes to showcase your problem-solving skills is the right advice and plenty of practice. That’s why, during the HEC Paris Career Center’s recent full-day workshop, “Careers in Digital Marketing & Tech,” the Careers team asked Sébastien Ritter, MBA ’10, to share his insights. The career coach and HEC Paris MBA alumnus is the founder of, a company that has helped over 200 applicants receive job offers from top firms like McKinsey, The Boston Consulting Group and Bain and Company.

Over 60 HEC Paris MBA students viewed his two-and-a-half hour online presentation. Unsurprisingly, participation was very high as he guided participants step-by-step through the process of solving the case interview.

Sébastien’s top 5 case cracking tips:

1. Remember there is no “correct” answer

The goal of any hiring process is for the interviewer to get to know you better. With that in mind, your first response to any analytical question should be to stay calm and project confidence. “I’ve seen a look of panic cross people’s faces when they are asked to solve a business problem,” Sébastien explains. “Understand that the interviewer is looking for insights into how you think and solve problems, and is not looking for a ‘correct’ answer.”

Sébastien says to explicitly explain the logic behind your answer, and to openly share your thought process. Your goal in answering is twofold: to think through the problem and to build a good relationship with the interviewer.


A picture of two women sat either side of a table in formal attire discussing an issue. It looks like an interview2. Understand the question completely

Very often, the analytical questions presented during job interviews are deliberately vague or general. When that happens, Sébastien says to ask the interviewer for clarification on any of these five points:

    • What is the measure they are seeking in terms of volume or value? (In the case of the iPhone question, they are seeking the number of units sold per year)
    • What is the timeframe?
    • Where is market? Clarify the geographical region before getting started.
    • Define the exact product you are examining (Which model of iPhone, what colors and specifications, and does the question concern only the sales from the first-hand market, or are refurbished models to be included as well?)
    • What alternative solutions do people have? (Other mobile vendors competing against the iPhone include Samsung, Huawei, etc.) 

3. Structure your problem-solving

Interviewers are seeking to hire candidates with a clear plan, so don’t randomly jump from one aspect of the analysis to another. “This approach is like counting on luck to solve the problem,” Sébastien explains.  “Instead, develop a structured approach.” Your technique should show all the key components of the problem. Next, analyze those key components in order to find, with certainty, a solution.

4. Perform your calculations using the following principles

    • Always justify your assumptions. Remember, the aim is to show how you think.
    • Your calculations must be quick and accurate. Case cracking questions typically require only elementary math skills, so if you aren’t quick and accurate in responding, it will not reflect very well on your processing skills.
    • Do your calculations out loud. Explain what you are doing, rather than doing quiet calculations on paper. This allows the conversation to keep flowing, and more clearly illustrates your thinking process.

5. Practice makes perfect

The more you work on your problem-solving skills, the more prepared – and relaxed – you’ll be during the interview. Sébastien invited anyone looking for more practice with the case cracking part of an interview to tackle the many examples posted on his company website here and here.


Other hiring tips for Digital Marketing and Tech

The second part of the all-day seminar featured four experts’ advice on working in digital marketing and tech. After each presentation, the HEC Paris MBA students had the opportunity to ask questions. A few highlights:

Question: What can I expect from the hiring process when I’m interviewing for a managerial role in digital marketing?
“Our hiring process at fifty-five usually includes 6 interviews. We evaluate motivation, knowledge of the sector and include some business cases involving web analytics. My advice is to build some knowledge in digital marketing – which you will gain from your MBA classes – and prepare your talking points before the interviews. –Charles Duenas, Consulting Manager at fifty-five 


QuestionI feel overwhelmed by the tools of digital marketing. Should I be concerned about my ability to find a job if I am not that comfortable with them?
“As MBA students, you will be interviewing for leadership roles, roles in which you will be continuously integrating qualitative data and quantitative data insights. For these type of roles, it is not critical for you to know how to program in every analytical tool out there.What matters is for you to understand the quality of the outputs coming from these tools, and to be able to check with a programmer/statistician that you are correctly interpreting the results.

A picture of HEC Paris associate professor Anne-Laure Sellier

Associate Professor Anne-Laure Sellier

Consider machine learning. You may learn how to conduct machine learning, which involves considerable algebra. It’s fun! However, machine learning is evolving fast, and it will be hard to keep up without becoming an expert. As an MBA, my recommendation instead would be to understand:

  • what the key assumptions of machine learning are (at the moment)
  • when its use is proving reliable in business practice (at the moment)
  • when its use should be avoided/for what reason(s)

In other words, you need to know enough about machine learning to have a common language with the engineers, and understand what they are doing. The heart of your job as an MBA will be about integrating the kind of insights you would get from machine learning (with the help of experts in your team) with insights from other marketing research methods, and develop an impactful marketing plan using these integrated insights.

In sum, knowing how to analyze data is always great as long as you have time and motivation to do it in detail, but knowing how to take action on that analyzed data should remain your main focus.” -Anne-Laure Sellier, Associate Professor of Marketing at HEC Paris


Question: Are companies seeking only people who have an IT or engineering background for their digital marketing roles?
“Some companies are, sure, but most aren’t, for the exact reason I mentioned before. If decision-making is what these roles require, it is a different skill from data analysis. Of course, if you have both skills, analyzing the full data yourself and taking action, it’s great. But the best decision-makers are not necessarily the best analysts.

In fact, many companies with strong engineering cultures want to bring in people with different backgrounds to encourage a variety of original ideas. In general, you will not need a great deal of technical expertise, with the exception of certain types of companies: some start-ups or bio-engineering firms, for example. The crux, for MBA students, is to acquire this ability to integrate vast amounts of data outputs and act upon this integration. If you are to use specific tools for a specific job, you will often get tailored training on it in-house.” -Anne-Laure Sellier, Associate Professor of Marketing at HEC Paris