INTERVIEW GUIDE

McKinsey Business Analyst Interview: Case & PEI Process

The McKinsey Business Analyst interview is built on two things: the case interview and the Personal Experience Interview (PEI). Cases test structured problem-solving — frameworks, market sizing, and quantitative reasoning — while the PEI digs into real stories of personal impact, leadership, and drive. Most candidates first pass the McKinsey Solve digital assessment, then face two rounds of interviews that pair a case with a PEI each.

The interview process

1. Resume & cover letter screen — application review

Tests: academic record, leadership, and evidence of analytical achievement

2. McKinsey Solve assessment — game-based, ~60-70 min online

Tests: problem-solving, decision-making, and data interpretation through interactive scenarios

3. First round: case + PEI — two interviews, ~45 min each

Tests: a business case plus a Personal Experience Interview on a real leadership or impact story

4. Final round: case + PEI — two to three interviews, ~45 min each

Tests: harder cases with senior interviewers and deeper PEI probing

Questions you're likely to get

Technical

Given this exhibit, calculate the breakeven volume and tell me what it implies.
If fixed costs are $2M and margin per unit is $40, how many units to break even — and what raises that risk?

Role-specific

Our client, a regional airline, has seen profits fall for three years. How would you diagnose why?
A retailer is considering entering a new country market. How would you evaluate the opportunity?
Estimate the number of gas stations in the United States.
A manufacturer's costs are rising faster than revenue. Walk me through how you'd find the driver.
How would you size the market for electric vehicle charging in a mid-sized city?
A client could grow by acquisition or organically. How would you structure the decision?

Behavioral

Tell me about a time you led a team through a difficult situation (PEI: leadership).
Describe a time you had to persuade others who initially disagreed with you (PEI: personal impact).
Tell me about a goal you pursued against significant obstacles (PEI: entrepreneurial drive).
Why McKinsey, and why management consulting at this point in your career?

How to answer (worked examples)

The client's profits have fallen for three years. How do you diagnose it?

Ask for a moment to structure, then lay out a clear tree: profit = revenue minus costs. Break revenue into price x volume (by segment) and costs into fixed vs variable. State your hypothesis for where the problem likely sits, then ask for the data to test it. Drive the case — don't wait to be fed numbers — and tie every branch back to 'so the client should...'. McKinsey scores structure, prioritization, and a crisp recommendation, not just math.

Estimate the number of gas stations in the US.

Talk through your logic out loud and pick a clean anchor — e.g., population, cars per person, or stations per town. Build top-down or bottom-up, state assumptions explicitly, and keep the arithmetic simple and round. Sanity-check the final number against reality. They don't care about the exact figure; they care that your structure is sound and your assumptions are defensible.

Tell me about a time you led a team through difficulty (PEI).

Pick one story you can go deep on, and use a tight structure: the situation and stakes, your specific role, the actions YOU took (not the team's), and the measurable result. Expect the interviewer to drill into your thinking and emotions — 'why did you do that?', 'how did others react?'. Depth and self-awareness beat a polished but shallow story. Prepare two to three distinct PEI stories so you don't reuse one.

What Mckinsey looks for

Structured problem-solving — clean, MECE frameworks tailored to the specific case
Quantitative comfort — quick, accurate mental math and confident exhibit interpretation
Business judgment — you prioritize the issues that matter and synthesize a recommendation
Personal impact and leadership backed by specific, deep PEI stories
Drive, ownership, and clear communication under pressure
Red flag: a memorized framework forced onto the case, weak math, or PEI stories with no real 'I' in them

FAQ

What is the McKinsey Solve assessment?

A game-based online assessment (the successor to the old problem-solving test) that measures problem-solving and decision-making through interactive scenarios, often ecosystem-building and data tasks. It typically gates whether you advance to interviews.

What is the PEI?

The Personal Experience Interview — the behavioral half of each interview. Interviewers probe one of your stories deeply across dimensions like personal impact, leadership, and entrepreneurial drive, pushing into your reasoning and choices. Prepare a few detailed, distinct stories.

How many cases will I actually do?

Usually four to five interviews total across two rounds, each pairing a case with a PEI. Final-round cases tend to be harder and led by more senior interviewers.

Do I need to memorize frameworks?

Know the classics (profitability, market entry, market sizing) but don't force them. McKinsey rewards a custom structure built for the specific problem over a textbook framework applied blindly.

How important is mental math?

Very. You'll calculate breakevens, growth rates, and market sizes live. Practice fast, accurate arithmetic and reading data exhibits under time pressure.

Case-prep is a spoken skill — train it that way

You can read frameworks all day, but cases and the PEI are won by thinking out loud, clearly, under pressure. Practice this exact interview — structuring a case live and telling tight PEI stories — with OfferLoop's realtime voice coach before round one.

Practice this interview out loud →

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Interview formats vary by team, level and year, and this guide is compiled from general knowledge of publicly discussed hiring processes — treat it as preparation material, not an official description of Mckinsey's current process.