This one took me a minute to get my footing.
Start by clarifying requirements and scale (e.g., number of services, secret types, rotation frequency) before diving into architecture. Then propose a high-level design covering storage, access control, and distribution, and drill into trade-offs for each component. Finally, discuss how secrets are securely delivered to services and handle rotation and revocation.
Pro tip: Emphasize security best practices like encryption at rest and in transit, least privilege, and audit logging, and mention how you'd handle secret rotation without downtime—this shows production maturity.
Ask about the number of services, secret types (API keys, DB credentials, certificates), expected read/write QPS, and compliance needs. This scopes the design and shows you avoid over-engineering.
Outline components: API server, storage backend (e.g., encrypted etcd or a database), access control layer, and secret distribution mechanism. Explain how they interact and scale.
Describe how secrets are stored encrypted at rest using a master key (e.g., KMS), and how you handle key rotation. Discuss trade-offs between using a dedicated secret store vs. a general database.
Explain authentication (e.g., mTLS, JWT, IAM) and authorization (e.g., RBAC, ABAC) models. Detail how policies are defined and enforced, and how to audit access.
Cover how services retrieve secrets (e.g., sidecar, init container, API call) and how secrets are rotated and revoked without disrupting services. Mention caching and lease-based access.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.