Celebrity profile cache stampede
Design the caching layer for a celebrity-account read path on a social network where a single profile/timeline key can be requested 500k times/second during a viral moment. Reads dominate writes 10000:1, but a profile edit must reflect within a few seconds. You have a Redis fleet in front of a sharded Postgres. Walk through how you keep a single hot key from melting one shard, and how you avoid a cache stampede when that key expires.
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.
Clarify5:00 left
Estimate5:00 planned
Design15:00 planned
Deep dive12:00 planned
Failure8:00 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.