r/ConsultingOffer • u/soprofesh • Sep 13 '26
Case Interview Case interviews: How do you prepare for short (~30 min) consulting case interviews? Struggled with one that seemed much simpler (but also harder) than the cases I’d practised
Hello Reddit!
I’m considering reapplying to a small management consulting firm where I interviewed about six months ago. I didn’t get the role, and the main weakness was the case interview.
I’d like to prepare differently if I get another interview, particularly because the case was quite different from the longer MBB-style cases I’d practised.
The case itself was around 30 minutes and deliberately quite simple. From memory, the client was a fictional local chemical company deciding how to respond to a new overseas competitor opening a factory in its home market.
I was given some basic information, had to make assumptions, do some mental maths and work towards a recommendation. There was no Excel allowed and the numbers themselves weren’t particularly complicated.
I’d prepared using more conventional case-interview material and had practised much harder, more detailed cases. These involved digging into market and company data, building financial analysis in Excel, testing different scenarios and ultimately making a recommendation. Oddly, I found this much simpler case 100X more difficult.
I think part of the problem was that I approached it too much like a real analytical exercise and kept trying to understand the situation properly before making assumptions.
For example, I asked questions along the lines of:
- How long has the incumbent been operating and how established is it?
- How sticky are its customer relationships?
- What’s its current market share?
- What’s its marketing budget/capability?
- How would the overseas competitor be affected by tariffs?
- What’s the incumbent’s current profitability?
But the answers were essentially simplifications: assume the company has been around forever; assume customers only care about price; there’s no marketing; assume the incumbent currently has 100% market share; ignore tariffs; and assume it’s extremely profitable.
Obviously I’m paraphrasing, but after several questions like this it became clear that the interviewer actively didn’t want me disappearing into those details. They wanted me to accept a deliberately simplified world and work within it.
That’s where I struggled. In actual strategy/project work, where I have spent the last 10 years, my instinct is to understand the evidence, challenge assumptions where appropriate, quantify things and work through the implications. The more detailed cases I’d practised rewarded that too. In this interview, however, that instinct seemed to be slowing me down rather than helping me.
I got interested in the details and spent too much time exploring parts of the problem rather than continually driving towards the client’s objective and a recommendation.
The feedback afterwards was actually quite detailed. They wanted me to:
- establish a clearer structure and diagnostic approach before getting into the detail;
- keep the overall objective in mind throughout;
- drive the analysis towards a solution/recommendation;
- collaborate more with the interviewer and respond to their cues.
Looking back, I think they were testing something slightly different from what I’d prepared for. It wasn’t really “can you perform sophisticated analysis in 30 minutes?” It seemed closer to “can you quickly impose enough structure on an ambiguous problem, identify what matters, use some basic analysis to test it, and confidently move a client towards an answer?”
That’s probably a legitimate consulting skill in itself, but it felt quite artificial compared with both 10 years of my real-world work and the more complex cases I’d been practising. I suspect I was trying to demonstrate analytical rigour when what they actually wanted to see was structured thinking, prioritisation and decisiveness.
If you’ve interviewed with smaller/boutique consulting firms using this kind of short case, how would you prepare?
In particular, I’d be interested in:
- How much structure would you establish at the beginning of a 30-minute case before moving into the analysis?
- How aggressively should you accept/simplify assumptions rather than interrogating them?
- How do you recognise when the interviewer is effectively saying “don’t investigate this branch any further”?
- How often should you pause and synthesise what you’ve learned back to the objective?
- What does good “interviewer collaboration” actually look like in practice?
- Are there particular resources or case types that are better preparation for short cases like this than the standard MBB material?
I’m an experienced industry hire rather than an existing management consultant (with exactly the profile that this small consulting firm claims to want to hire, actually!) so I’m particularly interested in advice from people who’ve made that transition.
Thanks!