MBB · Boston Consulting Group
BCG case interview prep: what they test and how to train
TL;DR
BCG cases sit between McKinsey and Bain in format. They are mostly candidate-led but with more interviewer probing than Bain. BCG screens with the Casey chatbot interview in many regions, then runs two to three live case rounds. The firm pays particular attention to creative insight: candidates who deliver an unexpected angle in synthesis stand out.
Last updated: May 16, 2026. Written by the CaseXcel team.
What the BCG case interview tests
BCG cases test structured analysis combined with business judgment. You will be asked to size a market, work through a profit or growth case, and synthesize. The math is usually moderate; the differentiator is the quality of your "so what" — whether you can pull a non-obvious implication from the data rather than just restating it.
BCG-specific screeners
BCG Casey (Chatbot Case)
A pre-recorded chatbot interview that walks you through a structured case via typed responses. Tests structure, math, and prioritization in a constrained format. Mental math and quick MECE structuring matter more than communication polish here.
BCG Online Case (region-dependent)
Some offices use a written online case in addition to Casey. Format and difficulty vary by office.
Why strong candidates still fail
- Solid math, dull synthesis. BCG remembers candidates who say something interesting in the final recommendation.
- Skipping market sizing reps. Sizing comes up in BCG cases more than at Bain, and people who have not practiced visibly struggle.
- Treating Casey like a chat. It is graded on substance, not chatbot rapport.
Prep tactics that move the needle
Practice extracting the non-obvious insight
After every case drill, force yourself to write one sentence that is more interesting than "revenue is down because volume dropped."
Drill market sizing weekly
Fermi-style top-down decomposition shows up in BCG cases routinely. One drill a day for two weeks gets you fluent.
Run a Casey-style mock
Simulate the format: time pressure, typed responses, no recovery if you go down a wrong path. Builds composure for the real thing.
Train the skills BCG actually tests
Mental math, case math, market sizing, MECE structuring, and framework recall, drilled in a single 5-to-10-minute daily session. No accounts, no onboarding, no fluff. The same practice that gets BCG candidates ready for the case.
FAQ
How is BCG Casey different from a live case?
Casey is a typed chatbot interaction with strict time limits per question. There is no interviewer to recover with. You need to be MECE on the first attempt and your math has to be right the first time.
Is BCG more or less quantitative than McKinsey?
Slightly less quantitative on average, but with broader case types (more growth strategy, market sizing, and synthesis-heavy prompts). The math you do is shorter; the quality of your insight matters more.
How long should I prepare for BCG?
Four to eight weeks of daily practice. Allocate dedicated time to Casey if your region uses it — its constraints are different enough that without targeted prep, candidates who would pass a live case still stumble.