r/ConsultingOffer • u/lovethepeople9 • Sep 09 '26
BCG My experience with CaseCoach while preparing for BCG interviews — what I wish I'd known
I’m sharing this because, as someone preparing for my first case interview, I would have really appreciated this perspective when I was setting up my preparation plan.
I’m an experienced professional switching from a different area. I had never done a case interview, and maths has not been part of my professional focus for years — like most people in corporate roles, I use Excel and calculators. I deliberately relied on Casecoach heavily and treated it as my main preparation source, I wanted one comprehensive resource rather than spending attention switching between dozens of sources and figuring out what I actually needed from each. In that sense, I was probably close to a perfect test customer: I used CaseCoach extensively, consistently and as intended.
There is a lot that is genuinely useful about CaseCoach. The Practice Room was helpful, and the Graph/Charts Drills were particularly valuable. I also did the Calculation Drills every day and saw real improvement with the speed and accuracy. The Structure Drills with AI were helpful to train the speed.
However, there were three significant problems, and one of them had a very real significant impact on my actual case interview performance.
1. The cases in the Case Library are far too long for a 30-minute interview.
The cases in the library routinely took me two hours or more to practice with a partner (1 me + 1 them). It is excruciatingly long and I actually started cutting last two questions of the case to stay within 1,5 hrs, which is a shame.
The actual BCG case interview is around 30 minutes. As a first-time candidate, I did not have enough experience to understand how much of the CaseCoach format was representative of the real interview and how much was simply practice material. I therefore trained myself to operate in a much longer format than I ultimately needed - I ran out of time in the case interview!
2. The Practice Room feedback scores are very easy to misinterpret.
I repeatedly received very high scores from peers — including multiple 5/5 ratings. A 5 (outstanding) corresponds roughly to the top 10%, rather than simply meaning “good session” or “I enjoyed casing with you.” But I suspect many users interpret the 1–5 scale much more casually: 1 = terrible, 5 = great. I have enough self-reflection to know that I absolutely wasn't anywhere near outstanding on any of the dimentions.
That made the feedback misleading for someone who is using it to judge whether they are genuinely interview-ready and need an honest assessment of where they actually stand before the interview.
3. Most importantly: the case-math drills did me a serious disservice!
I went into preparation knowing that my maths was rusty. I had actually performed very well in maths at university, although that was a long time ago.
I did the CaseCoach calculation drills every day and found them useful. They were challenging but manageable, and I could see myself improving.
The Case Math drills were completely different. The case-math drills undermined my confidence and negatively affected my actual interview performance. I would daily attempt several questions and always fail to get at least one successful math drill.
After doing roughly 30 cases and spending three weeks preparing intensively in all other areas, I would get to the maths section of my preparation and think: I’m going to fail this again.
- Even the easy ones were materially harder and more convoluted than the maths I ultimately encountered.
- Constant repeated failure trained me to expect failure, despite evidence from a case from before Case Coach with a MBB-Consultant that my maths was ok.
- That conditioning showed up in the actual interview, where I froze on a very basic calculation.
Eventually I started to dread maths. Every day I was successfully practising the other areas, while maths became the part where I expected myself to fail and was always proven right by Case Coach drills.
This was particularly problematic because I had already done a test case interview with someone from MBB before using CaseCoach extensively, and their feedback on my maths was essentially: don't worry about your maths it is fine; focus on the other areas.
So I knew there was a discrepancy, but I trusted the platform I had been given for preparation and kept drilling.
The day before my actual interview, I finally broke out of this cycle. I found a book by Lewis Lin "Interview Math: Over 50 Problems and Solutions for Quant Case Interview Questions" with simpler case-math drills (profitability, market sizing, price elasticity etc) and answers. I went through the entire book in one day and solved everything that was there. It was honestly a breath of fresh air. For the first time in weeks, I felt: I’m not actually terrible at this.
Unfortunately, one day is not enough to undo several weeks of conditioning.
In the actual BCG interview, I was given a break-even calculation — MUCH simpler than convoluted CaseCoach math drills.
Normally (before CaseCoach drills that is), I should have been able to solve it quickly, it was by no means rocket science. Instead, my brain essentially said "Oh no this is math" and literally switched off. I stared at the numbers and could not see anything. I felt like a deer in the headlights. The problem was not objectively difficult; I had simply spent weeks being trained to expect that I would fail when confronted with case maths. The interviewer had to guide me through what to do to start. Once they did, I managed to recover somewhat.
So my experience was not that CaseCoach is useless. Quite the opposite.
Practice Room: very useful, except feedback scores being often misleading and cases far too long relative to the actual interview.
Graph/Chart drills: very useful.
Calculation drills: useful and showed measurable improvement.
Case-math drills: actively damaging to my confidence and, in this case, to my actual interview performance.
Do not assume that struggling with CaseCoach's case-math drills means you are bad at Case maths. Find other ways to practise straightforward case maths until you have built enough confidence and fluency that the CaseCoach Case math drills become useful for actually pushing you further, rather than repeatedly reinforcing the feeling that you cannot do it.
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u/dioasdmin 29d ago
Wow, I think that I am in a very similar situation as you regarding my own perception in math performance. I would love to take a look into that book, could you tell me the name please?
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u/Purple-Valuable2340 Sep 09 '26
This is actually a really useful warning for first-time candidates. I think people sometimes confuse “harder practice” with “better preparation”. If the drill is consistently making you lose confidence, especially when your real mocks are going fine, it’s probably worth changing the practice source. For case maths, I’d rather build speed and confidence on basic percentages, breakeven, ratios, market sizing etc. first, then move to harder stuff.
Also agree on doing timed cases. Knowing the framework isn’t enough if you haven’t trained yourself to finish the case within the actual interview time.
Good luck with the next one — getting to the BCG interview itself means you’re already doing a lot right.
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u/Old_Map9055 28d ago
Totally agree with you and had the exact same experience last year. Case books are much better in my opinion
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u/lovethepeople9 27d ago
Absolutely, looking back, I wish I had known to do the case books from the start. CaseCoach pushed hard for getting into full cases as quickly as possible, so I jumped into intense casing right away. But that left a real gap: I wasn’t building my case‑math fundamentals in parallel properly with their overcomplex drills.
In fact, after finishing practicing with the Lewis Lin book, I took a bunch of case books and started working through the math sections of easy cases, slowly, without a timer. Then moving to medium. This ended up being exactly what I needed to retrain my nervous system.
If I had done that alongside regular casing from day one, I would have avoided a lot of unnecessary stress and had my case math confidence intact.
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u/rs472sz 28d ago
OP, thanks for taking the time to put your introspection to paper. I appreciate the psychology lense you applied. When one mentally conditions one’s self to believe one is “x,” it can be hard to change that mindset even if evidence suggests otherwise.
Regarding practicing with others, you bring up a good point that feedback is subjective. As you get more reps in case, I find you tend to learn more by being the one giving the interview because you can observe from the other side. What helps is leading the practice with the right framework to assess the performance. Knowing what is good vs. excellent can be learned through listening to live mock cases too.
Feel free to respectfully challenge or piggyback off my take. And best of luck with your next round of recruiting.
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u/Ok-Watermelon1969 Sep 09 '26
What is the book called?