What is a case interview?

What a case interview is

A case interview is a conversation in which you and the interviewer work through a business problem together, out loud, usually in 30 to 45 minutes. The problem is fictional but realistic: a beverage company watching its margins slide, a supermarket chain wondering whether to open in a new region, a software firm deciding how to price a new product. There is no single right answer on the table. What is being examined is the road you take: can you take a vague, information-poor question and turn it into a structure, gather the facts you need, do honest arithmetic on incomplete data, and finish with a recommendation you can defend?

Consulting firms use the format because the work itself looks like this. A first-year consultant is handed an ambiguous question by a partner, expected to break it into pieces, and then to close each piece with analysis and a clear point of view. The case interview is a one-hour rehearsal of that job. Candidates from any degree background pass them; what separates a pass from a fail is rarely knowledge and almost always the discipline of the thinking you show.

The format, part by part

Formats differ across firms, but almost every case is built from the same five parts. Learn to recognise them and any interview becomes navigable, because at each moment you know what is being asked of you.

Two habits carry candidates through all five parts. First, answer first: lead with your conclusion, then support it, in the synthesis and everywhere else. Second, think out loud: the interviewer cannot score silent thinking, so narrate your path even when you are unsure, and say explicitly when you are weighing trade-offs.

The common case types

Under the surface variety, cases recycle a small set of commercial questions. You will meet the same families again and again, in interviews and in practice.

How the firm formats differ

The big three firms run the same five parts with different accents, and each pairs the live interview with its own digital assessment.

McKinsey is interviewer-led: the interviewer steers the conversation from part to part, so you are never lost for long, but you are also never in charge. Before the live rounds sits McKinsey Solve, a game-based digital assessment, with the Redrock study testing how you work through a data-heavy case; both have their own deep-dive guide on this site.

BCG cases lean candidate-led and quantitative, and BCG now fronts its process with Casey, a chatbot-run case, plus a quantitative reasoning check; we cover both in the BCG Casey guide. Expect more numbers per minute than McKinsey and more ownership of the storyline.

Bain runs a candidate-led case that is famously pragmatic, and its online stage is the SOVA test battery plus a one-way video interview; the SOVA numerical guide and the HireVue video guide walk both. The case itself often hangs on a real Bain engagement story.

If you want to feel the format rather than read about it, Case Ace is an AI case interviewer that runs full practice cases question by question; the Case Ace page shows how a run works and what the scored report looks like.

A worked example

Here is a prompt in the classic shape: "Our client is a mid-sized coffee roaster. Revenue is flat but profits fell 15% last year. Should they be worried, and what would you look at?"

A strong opening does three things in about two minutes. It scopes: "Flat revenue with falling profits points at costs or mix rather than the top line; I would like to confirm whether the fall is industry-wide or specific to us." It structures: "I will look at three things: price and volume by product line, the cost base, and any one-off items." And it hands control back: "Shall I start with the revenue mix?" From there the interviewer feeds you data, you run the arithmetic out loud, and you close with an answer to the question actually asked, worry or no worry, and what to do about it.

Notice what the strong opening did not do: it did not recite a generic framework, it did not ask for a month to think, and it did not bury the recommendation. That is the whole game in miniature.

How to prepare for your first case

Preparation divides into four lanes, and first-timers over-invest in the wrong ones. In order of return:

• Learn the arc of a case, the five parts above, until you can name where you are in any moment of an interview. Without this, everything else is trivia.
• Drill the maths until the arithmetic is boring: percentages, breakevens, market sizing, reading a chart under time. Most lost offers die here, not in strategy.
• Practise out loud, alone at first, then with a partner who will interrupt you the way a real interviewer does. Silent practice builds false confidence.
• Get feedback on structure, not charm. The failure modes, a framework that ignores the question, a synthesis that answers a different question, are specific and fixable.

A sensible first week: two sessions on the case arc, three drills of mental maths per day, and one full case walked through out loud, even with nobody grading it. That is enough to make your first live practice case productive instead of frightening.

Frequently asked questions

How long does a case interview take?

The live case usually runs 30 to 45 minutes inside a longer interview slot, with 5 to 10 minutes on your questions at the end. Digital assessments in front of the interview vary: McKinsey Solve takes roughly 70 minutes, BCG's Casey chatbot about 25 to 30, and Bain's SOVA battery is self-paced per section.

Do you need business knowledge for a case interview?

No. Interviewers do not expect industry expertise, and cases are written so a clever non-specialist can attack them. You do need a small stock of commercial concepts, margins, market share, fixed versus variable costs, and the habit of reasoning with them out loud.

What happens if you get stuck in a case interview?

Say where you are and re-anchor in the structure: "I have lost the thread on pricing; the branch that matters more is volume, so let me go back there." Interviewers score recovery. A candidate who names the stall and restarts cleanly often finishes stronger than one who never stumbled.

Are case interviews still used for consulting hiring?

Yes, at every major firm, now alongside digital assessments rather than instead of them. The direction of travel is more screening upstream, the chatbots, games and test batteries above, with the live case reserved for candidates who clear it, and the live case itself unchanged in what it scores.