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.