Grocery typeahead with inventory
Design search typeahead for an online grocery store. As a shopper types, suggest products, categories, and recent items. Constraints: tolerate typos ('avacado'), rank by what's in-stock and locally available at the shopper's store, p99 under 70ms, and a catalog of 2M SKUs that varies by store (availability changes hourly).
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.
Clarify4:30 left
Estimate4:30 planned
Design13:30 planned
Deep dive10:30 planned
Failure7:00 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.