Case interviews: how they work and how to prepare

A case interview is a simplified, realistic business problem that you work through with the interviewer. The interviewer holds the facts and hands them out when you ask the right questions. Your job is to show how you would think through the problem, not to know the answer in advance.

Cases are best known from management consulting: the strategy firms, the consulting arms of the Big Four accounting firms, and boutiques. They are also common for in-house strategy, corporate development, product management, business operations and some marketing, sales-leadership and HR business-partner roles. See the role guides for how each one uses them.

Most cases are one of ten types. Each links to a full practice case from MECE's US bank.

In an interviewer-led case, the interviewer walks you through a fixed set of questions: lay out a structure, read this chart, run this calculation, give a recommendation. McKinsey is best known for this style. In a candidate-led case, you decide what to analyze next and ask for the data you need. It is common at BCG, Bain and many other firms. Styles vary by office and by interviewer, so prepare for both.

1. 1

   Clarify (1–2 minutes)

   Repeat the question in your own words. Confirm the objective (profit, market share, growth?), the timeframe and any constraints. Ask about anything you genuinely do not understand, like the business model. Do not ask for data you do not need yet.

2. 2

   Structure (2–3 minutes)

   Ask for a moment, then present a MECE structure with three or four branches tailored to this case. Walk through it top-down and say which branch you would start with and why.

3. 3

   Analyze (15–25 minutes)

   Work branch by branch. Ask for data, do the math out loud, and after every number say what it means for the client. Update your hypothesis as facts come in.

4. 4

   Recommend (1–2 minutes)

   Lead with the answer, give two or three reasons with numbers, then name the risks and next steps. Use the Pyramid Principle: answer first, support second.

Firms do not publish their rubrics, but they assess the same core skills. MECE scores every practice attempt out of 100 on six dimensions that mirror them:

Here is the first two minutes of a fictional case, showing clarification and a structure.

A four-week plan works for most people who already know basic business concepts. Adjust it to your weakest dimension.

• Reciting a memorized framework instead of building one for this client. Interviewers notice.
• Asking for data without a reason. Say what you expect it to show and why it matters.
• Doing math silently. Talk through your approach so the interviewer can follow and correct you.
• Reporting numbers without a "so what". "Costs rose 12%" is data. "Costs rose 12%, which explains most of the lost profit" is insight.
• Ending with a summary instead of a recommendation. Commit to an answer, even with caveats.

Yes. The format changes but the skill is the same. Product managers get estimation and metric-diagnosis questions. Sales leaders get territory and quota problems. HR leaders get attrition and workforce-planning cases. Finance roles get variance and business-case questions. Start with the guide for your role:

• Product manager case interviews
• Sales case interviews
• Marketing case interviews
• HR case interviews
• Strategy and operations interviews
• Finance case interviews