Enterprise semantic search
Design enterprise search across a company's internal docs, wikis, chat, and tickets (10k employees, ~500M documents). Queries are natural-language ('how do I expense a conference') and must return the right doc even with no keyword overlap. Constraints: strict per-document ACLs, p95 under 400ms, and freshness within minutes of a doc edit.
What a strong answer looks like
Clarify scale and constraints first. Propose a clean component breakdown, then go deep on the hard parts (data model, bottlenecks, consistency, failure modes) and name the trade-offs you are making.
Clarify6:00 left
Estimate6:00 planned
Design18:30 planned
Deep dive14:30 planned
Failure10:00 planned
Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.
Run or narrate your approach, then ask the coach.