A case interview your friend can lead, with the data already written
Sergei Skrylkov, Founder, Trippi · facts checked against the product on 2026-09-30
Case interview practice needs a friend who has the data and knows when to give it. In a real consulting case the interviewer holds numbers back until you ask for them, and part of the test is asking for the right ones. This page gives your friend a complete case — the prompt, the data, and the order of the questions — so they can lead it without any consulting background.
Setup
- Your friend reads only this page; you do not. Send them the link and do not open it yourself.
- Call in Google Meet, or Zoom or Teams in the browser. Keep paper and a calculator at hand; most firms allow paper, not always a calculator — agree which before you start.
- The case is interviewer-led: your friend asks the questions below in order and gives data only when you ask for something close to it.
The real round is described on the case interview page; practice calls in general on interview practice.
The case: a bakery chain’s falling profit
Prompt for your friend to read: “Our client is a chain of forty bakeries in one country. Revenue has grown slightly over two years, but profit has fallen by a third. The CEO wants to know why and what to do.”
- Revenue: 20m two years ago, 21m now.
- Costs: ingredients up from 6m to 8m; staff 7m to 7.5m; rent flat at 3m.
- Profit: 4m to 2.5m (fall due mostly to ingredients).
- Ingredients: flour and butter prices up about 30%.
- Prices: the chain has not raised prices in two years; competitors raised theirs by about 10%.
- Customers: visits flat; average spend per visit up slightly.
The script for the interviewer
- 1“Our client’s profit has fallen by a third while revenue grew. How would you approach this?” Follow-up: “Why that order?” — give the candidate a minute to structure
- 2“Where would you look first?” Follow-up: “What data would you want?” — hand over the revenue and cost numbers when asked
- 3“Which cost worries you most?” Follow-up: “What could be behind that increase?”
- 4“Ingredient prices are up about 30%. What are the client’s options?” Follow-up: “Which one would you test first?”
- 5“Competitors raised prices by 10%. What would a 5% price rise do to revenue if visits stayed flat?” Follow-up: “And if visits fell by 3%?” — a quick maths check; 21m × 1.05 is 22.05m
- 6“What risks do you see in raising prices?” Follow-up: “How would you find out how customers would react?”
- 7“Is there anything the client could do on the cost side instead?” Follow-up: “What would that cost them in quality?”
- 8“The CEO walks in. You have thirty seconds. What do you tell her?” Follow-up: “none” — the summary; one recommendation, two reasons, one next step
Timing
| Part | Minutes | Notes |
|---|---|---|
| Prompt and structure | 5 | Silence while the candidate writes a structure is normal; up to a minute. |
| Data and diagnosis | 10 | Questions 2–4. |
| Maths | 5 | Question 5. Your friend checks the numbers, not the method. |
| Options and risks | 7 | Questions 6–7. |
| Recommendation | 3 | Question 8, thirty seconds, then stop. |
| Feedback | 10 | Structure, maths, and whether the recommendation answered the CEO’s question. |
What your friend should listen for
- A structure out loud. Did the candidate say how they would break the problem down before asking for numbers?
- Asking for data. Did they ask for costs, or wait for them? Waiting is the weaker sign.
- The maths said aloud. In a real case, the interviewer follows the calculation. “Twenty-one times one point oh five” is better than a silent answer.
- A recommendation, not a list. The last answer should start with one decision — “raise prices by 5% in the stores with the least competition” — not with “there are several options”.
Switching roles
Swap with a different case: a market-sizing question (“how many electric scooters are rented in a city in a day?”) works well as the second one because it needs no data from the interviewer. The candidate states assumptions; the interviewer checks they are reasonable and asks for the calculation.
What Trippi Cue shows during this rehearsal
Case interviewers give numbers out loud, quickly, and in a second language it is easy to miss one. Every line your friend says — including “ingredients went from six to eight million” — appears in the Cue window as text, translated under it if you want, so you can check a number instead of asking again. For a question such as “what are the client’s options?”, the card offers a short structure, for example price, cost, mix. It does not do the maths and does not know the case; the numbers you use are the ones you heard.
It listens to the call tab after you click its icon, not to your microphone. It hears your friend and never hears you, so it cannot score or review your answer; the feedback comes from your friend. This is a rehearsal: use it to practise with a person until the answers come easily, then go into the real interview on your own. Where we stand on interviews.
FAQ
Case, specifically.
How do I practise a case interview with a friend who is not a consultant?+
Give them a written case with the data, like the one above, and ask them to hand over numbers only when you ask for something close. They do not need to judge the business answer; they check the structure, the maths and the recommendation.
How long is a case interview?+
Usually thirty to forty-five minutes for the case, often with a short fit part before it.
Should my friend help me if I get stuck?+
A little, as a real interviewer would: “What about the cost side?” Not the answer.
Can Trippi Cue calculate the numbers?+
No. It shows what was said and a short structure. The calculation is yours.
Read next
One bakery, eight questions, a thirty-second answer at the end.
Trippi Cue is in the Chrome Web Store. One click on the icon when the call begins, and nothing before that.