Secrets management vault
Design a secrets-management system (a vault) for an org with 8,000 microservices that must store and broker access to database credentials, API keys, and TLS private keys. It must support dynamic, short-lived database credentials minted on demand, audited access, and a master-key seal so that even root DB compromise of the vault's own store yields only ciphertext. Peak is ~50k secret reads/sec, p99 under 20ms, and a leaked secret must be revocable fleet-wide in seconds. Cover storage, the encryption/trust model, dynamic secrets, and rotation.
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.
Clarify5:30 left
Estimate5:30 planned
Design16:30 planned
Deep dive13:30 planned
Failure9:00 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.