Vacation rental ranking
Design the search-ranking system for a vacation-rental marketplace. A query (location + dates + guests) retrieves up to 10k eligible listings; you must rank them by predicted booking probability personalized to the user. Constraints: ranking adds at most 150ms over retrieval, the model is retrained nightly, and ranking must be consistent within a paginated session (page 2 follows page 1).
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.