Design a cold-storage observability system
Design a log/metrics cold-storage system for an observability platform. Constraints: ingest is tens of millions of events/sec at peak, recent data (hours) must be queryable fast, older data (months/years) is queried rarely and must be cheap, retention is years for compliance, and queries are mostly time-range + filter + aggregate. Cover ingest, the hot-to-cold path, and the query model.
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.