Latest / Interview Prep with Fexingo: Behavioral Questions, Case Studies, and Hiring Manager Insights / How to Answer the Consulting Case Interview Question
Transcript
- Lucas: So you're in a consulting interview, and the partner across the table slides a single sheet of paper toward you. It says: 'Our client is a mid-sized retailer. Profits have dropped twenty percent year-over-year. What's going on, and what should they do?' Luna: And you have — what, thirty minutes? And no prep time beyond that moment. Lucas: Exactly. That's the classic case interview format. And what separates candidates who get the offer from those who don't isn't whether they know retail — it's whether they can structure their thinking on the fly. Luna: So today we're going to walk through how to approach that exact scenario. A profitability case for a retailer. Lucas: Right. And I want to anchor this in something real. A few years back, I heard about a BCG interview case where the candidate was given a chain of forty home-goods stores. Revenue was flat, but profits had fallen by about fifteen percent. The candidate who got the offer started not with an answer, but with a clarifying question. Luna: What did they ask? Lucas: They asked: 'When you say profits, do you mean gross profit or net profit? And are we looking at same-store performance or including new stores?' That single question bought them thirty seconds of thinking time and showed the interviewer they knew where to look. Luna: So the first move is always to clarify the terms and the scope. Lucas: Always. Because if you launch into a solution without knowing whether we're talking about store-level EBITDA or corporate net income, you're solving the wrong problem. After clarifying, the next step is to build an issue tree. Luna: Issue tree — that's the structured breakdown, right? Like, profit equals revenue minus cost, and then you split each branch further. Lucas: Exactly. So you say out loud: 'Profit is revenue minus costs. Revenue is price times volume. Costs are fixed and variable.' Then you ask: 'Is the drop driven by revenue, costs, or both?' And you keep going. The interviewer wants to hear your logic, not just the final answer. Luna: And you need to be specific. Not just 'costs went up,' but which costs? Labor? Rent? COGS? Lucas: Right. In that BCG case, the candidate drilled into variable costs and found that shipping costs per unit had spiked because the retailer had switched to a premium carrier to improve delivery times. That was the root cause. Luna: So the issue tree led them to the real driver. But what about the other piece — the hypothesis-driven approach? Lucas: That's the next layer. Once you have your tree, you don't just explore every branch randomly. You form a hypothesis. For example: 'I suspect the profit drop is driven by a rise in variable costs, specifically shipping, because e-commerce returns have increased.' Then you test that hypothesis with a targeted question. Luna: And you'd ask the interviewer for data on return rates or shipping costs. Lucas: Yes. And the interviewer will give you a number. They might say 'Return rates went from eight percent to fifteen percent.' Now you have a clear path. You don't need to analyze rent or labor unless that hypothesis fails. Luna: So it's about being efficient. You're not trying to boil the ocean. Lucas: Exactly. And the final piece is synthesis. After you've gathered data, you need to give a recommendation that's concrete and actionable. Not 'reduce shipping costs,' but 'renegotiate the carrier contract to a regional provider, which could cut per-unit shipping by twenty percent, and implement a restocking fee for returns above ten percent.' Luna: And you'd tie that back to the profit impact. Like, 'This would restore about half the profit decline in six months.' Lucas: Right. The interviewer wants to see that you can connect analysis to a business outcome. So the structure is: clarify, build an issue tree, form and test a hypothesis, then synthesize a recommendation. Luna: What about when you get a case that's not profitability? Like, should we enter a new market? Lucas: Same structure applies. Market entry cases use the same logic: revenue potential minus costs of entry, plus competitive dynamics. The framework adapts, but the discipline of structuring stays the same. Luna: I think a lot of candidates worry about being too formulaic. Like, if they lean too hard on frameworks, they'll sound robotic. Lucas: That's a valid concern. But the key is to use frameworks as a tool, not a script. You say: 'Let me think about this using a simple profit tree.' That shows you have a method. Then you talk through it in plain English, not consulting jargon. Luna: And you can always say 'I'm going to make a few assumptions here — correct me if I'm wrong.' That keeps it conversational. Lucas: Exactly. The best case interviews feel like a problem-solving conversation, not a presentation. So one more concrete tip: practice writing issue trees on paper, but then practice speaking them aloud. Because in the interview, you're not drawing on a whiteboard — you're talking. Luna: So let's do a quick drill. I'll play the interviewer. You're in a case for a airline struggling with declining load factors. Go. Lucas: Okay. First clarifying question: 'When you say load factor, do you mean the percentage of seats filled on each flight? And are we looking at the entire network or a specific region?' Luna: Assume it's the entire domestic network, and yes, it's the percentage of seats filled. It's dropped from eighty-two percent to seventy-six percent over the past year. Lucas: Great. So I'll start with a profit tree, but since load factor feeds revenue, I'll focus there. Revenue per flight is seats times load factor times average fare. So either fares dropped, or load factor dropped. You said load factor dropped, so I'll start there. Possible drivers: less demand — maybe due to economic downturn or competition — or more capacity — maybe the airline added too many flights. Luna: Good. So you're already branching. Now what's your hypothesis? Lucas: My hypothesis is that demand hasn't changed, but capacity increased because the airline added five new routes last year without retiring old ones. That would dilute load factor. I'd ask: 'Did the airline increase total seat capacity year-over-year?' Luna: Yes, by about ten percent. Lucas: Then my recommendation is: cut underperforming routes or reduce frequency on low-demand days. Target a fifteen percent capacity reduction on the bottom quartile of routes, which should bring load factor back above eighty percent within two quarters. Luna: That's solid. You moved fast and kept it structured. I think listeners can see how the framework works in real time. Lucas: And that's the muscle you build with practice. The more you drill, the more natural it becomes. Before you know it, you're not thinking 'I need to use an issue tree' — you just start breaking the problem down. Luna: If this episode helped you think through case interviews more clearly, consider supporting the show. A couple of dollars a month genuinely makes a difference — it keeps us ad-free and focused on content like this. You can find that at buy me a coffee dot com slash fexingo. Lucas: Yeah, it's a small gesture that goes a long way. And it helps us keep bringing you practical interview strategies every week. Luna: So to wrap up: remember the four-step sequence — clarify, structure with an issue tree, hypothesize and test, then synthesize a recommendation. That pattern works across virtually any case you'll face. Lucas: And when you walk into that room, remember the partner across the table isn't looking for the right answer on the spot. They're looking for how you think. Show them a clear, logical path, and you've already won.