What is a case interview? Definition and example question
A case interview gives you a business problem, such as why a company's profit is falling, and asks you to work through it out loud in roughly 20 to 40 minutes. It's common in consulting and in some strategy, product and finance roles. The interviewer is judging how you structure the problem, handle numbers and explain your thinking, more than your final answer.
An example prompt
A made-up case of the kind consulting interviews use:
"Our client runs 40 gyms. Membership numbers are flat, but profit has fallen over the last two years. What's going on, and what should they do?"
Other common types are market sizing ("How many coffees are sold in this city each day?") and new market entry ("Should this retailer start selling online?").
How you talk through it aloud
- Play it back and clarify. "So profit is down, members are flat. Do we know if prices changed? And is this all 40 sites, or a few?"
- Ask for a moment, then lay out a structure. "Could I take thirty seconds to organise my thoughts?" Then: "Profit is revenue minus costs, so I'd like to look at both. On revenue: price per member and extra sales. On costs: rent, staff and equipment."
- Walk through it with signposting. "I'll start with costs, since revenue looks flat."
- Do the maths out loud. "If rent went up 10% across 40 sites at roughly £100,000 each, that's about £400,000 a year." Saying each step lets the interviewer catch a slip early.
- Say what you've found so far. "So rent explains part of it, but not all. Can I look at staffing?"
- Finish with a recommendation first, then the reasons: "I'd renegotiate the leases at the five most expensive sites, because…"
The numbers in step 4 are illustrative; in a real case the interviewer gives you the data.
What interviewers listen for
- A clear structure before diving in.
- Comfortable, careful arithmetic.
- Updating your view when new data arrives.
- A concise answer at the end, as if speaking to a client.
More on structures and practice is in how to prepare for a case interview.
Questions people ask
Who uses case interviews?
Consulting firms most of all. Some strategy, product management, banking and operations roles use shorter cases too.
Can I use paper or a calculator?
Paper is usually expected. Calculators often aren't allowed, so practise mental arithmetic with round numbers.
What if I get the answer wrong?
A clear, well-reasoned path with a small error often scores better than a lucky right answer with no structure.
How long is a case interview?
The case itself usually takes 20 to 40 minutes, often after some behavioral questions.