Interview prompt
Problem context
A platform encrypts billions of objects with per-tenant data keys wrapped by regional keys. A compliance mandate requires annual rotation and the security team needs emergency compromise response. Re-encrypting every object synchronously is impossible and key-service outages must not take down all reads.
Skills being evaluated
key hierarchy designrotation protocolscompromise containmentavailability trade-offs
The full reasoning guide is part of Pro
The scenario and evaluation focus above remain public. Pro unlocks the structured answer, trade-off analysis, follow-up probes, common weak answers, rubric, related reasoning, and any architecture diagram.
Sign in to continueWhat the full guide covers
Clarify the decision
Establish scale assumptions
Functional and non-functional requirements
High-level architecture
Data model and flow
Consistency and transaction boundaries
Failure modes and recovery
Security and privacy
Observability and SLOs
Capacity and cost
Alternatives and trade-offs
Evolution and migration
What Staff and Principal candidates should emphasize