Consulting case interviews for finance students, worked example

How does a case interview run, step by step?

Almost every case follows the same arc, whether it is a profitability problem, a market entry, or an acquisition. The interviewer reads a prompt, you ask a few clarifying questions, and then you are expected to drive. Some firms lead you question by question (interviewer led); others expect you to choose what to look at next (candidate led). The firm's own careers site usually says which, and it changes how you practice.

1. Listen and repeat the problem back in one sentence, including the goal and any number given.
2. Ask two or three clarifying questions: what does success look like, over what time frame, any constraints.
3. Ask for a moment, then lay out a structure of three or four branches that together cover the problem.
4. Pick the branch most likely to hold the answer and say why.
5. Work the data and math the interviewer gives you, out loud, and say what each number means.
6. Pull in charts or exhibits, read the one insight from each, and connect it to the question.
7. Finish with a recommendation, the two reasons behind it, the main risk, and the next step.

Where do finance students go wrong in a case?

Finance training is a real edge on the math, and a real trap elsewhere. Banking prep teaches you to answer exactly what was asked. A case rewards you for deciding what should be asked. Interviewers see the same mistakes from finance majors again and again.

• Jumping to a DCF or a multiple when the question is whether the client should enter a market at all.
• A framework that is all financial (revenue, costs, profit) with no customers, competitors, or operations.
• Doing the math silently, then announcing a number with no meaning attached.
• Never forming a hypothesis, so the case drifts from branch to branch.
• Ending on a summary of what you found instead of a clear recommendation.
• Treating the interviewer as a grader instead of as the client you are helping.

How do you size a market in a case? A worked example

Market sizing is the most common short case, and it is graded on clean logic, sensible round assumptions, and a sanity check, not on hitting the true number. Prompt: how much do US college students spend each year on coffee from coffee shops?

Say every assumption out loud and round so the math stays easy. The numbers below are assumptions for the exercise, chosen to be plausible, not facts to memorize.

1. Population: assume about 19 million college students in the US.
2. Segment: assume half of them buy coffee shop coffee regularly, so 9.5 million buyers.
3. Frequency: assume three cups a week across about 30 weeks of the school year, so 90 cups each per year.
4. Volume: 9.5 million x 90 = 855 million cups a year.
5. Price: assume 5 dollars a cup on average, drinks of all sizes included.
6. Market: 855 million x 5 = about 4.3 billion dollars a year.
7. Sanity check: about 4.3 billion over 19 million students is about 225 dollars per student a year, or roughly 7.50 dollars a week for an average school week. Plausible for a mix of daily buyers and students who never buy.
8. Close: state the number, the two assumptions that move it most (share of buyers and cups per week), and how you would test them.

Which consulting programs are open right now?

The table below is read from each firm's own careers site. Consulting is the most fixed of the paths: the window is Jun to Sep, fixed deadlines, usually one or two rounds rather than rolling. If a program shows Expected, plan your case practice to peak before that window, not after.

How should a finance student use their strengths in a case?

Lean on the finance where it actually belongs. Profitability cases are revenue minus costs, and you will break those down faster than most. Acquisition cases ask whether the target is worth the price, and you already know how to think about synergies and payback. Breakeven questions are a single line of algebra you have done many times.

A quick example of the right register: a client pays 2 million for a new machine that saves 50 cents a unit, and it makes 1 million units a year. Payback is 2 million / (0.50 x 1 million) = 4 years. Say the number, then the meaning: four years is acceptable if the machine lasts well beyond that and volume holds.

How should you practice for case interviews?

Cases are a performance skill. Reading about them helps for a week; live reps with a partner are what move you. A realistic plan for the month before your first interview looks like this.

1. Week 1: learn the arc above and do ten market sizings alone, timed, saying each step out loud.
2. Week 2: do four full cases with a partner, two as candidate and two as interviewer. Giving cases teaches you what interviewers listen for.
3. Week 3: drill mental math daily (percentages, large multiplications, growth rates) and do five more partnered cases.
4. Week 4: do cases with people who have been through the process, and prepare three fit stories about leadership, teamwork, and a hard problem.
5. Before each interview: read the firm's own case examples, which many firms publish on their careers sites.

Questions students ask

Do I need a framework book to pass a case interview?

No. Frameworks help you start, but interviewers mark down memorized ones. Build a structure that fits the specific question, with branches that do not overlap.

Can I use a calculator in a case?

Usually not. Plan for pen and paper math, round sensibly, and say your rounding out loud.

How many practice cases should I do?

There is no magic number. Stop counting and watch for the point where your structure, math, and final recommendation come out cleanly under time pressure in several cases in a row.

Is consulting good for getting into private equity later?

Consulting is one of the two common front doors to the buy side, with banking. PE operations roles and some deal roles hire from consulting.

Do consulting interviews ask finance technicals?

Rarely in depth. You may see breakeven, payback, margins, or a simple valuation inside a case, but not a walk through of a DCF.