AdvancedTechnical
5 min
Designing Idempotent APIs
APIIdempotencyReliability
Advertisement
Interview Question
What does idempotency mean in APIs, and how would you design idempotent operations in REST or gRPC services?
Key Points to Cover
- Explain idempotency in HTTP methods (GET, PUT, DELETE vs POST)
- Use idempotency keys for POST operations
- Ensure backend deduplication and retry handling
- Log and monitor idempotent request outcomes
Evaluation Rubric
Defines idempotency correctly30% weight
Designs idempotent operations in APIs30% weight
Uses idempotency keys effectively20% weight
Ensures retries don’t cause duplication20% weight
Hints
- 💡Think payment APIs as a key use case.
Potential Follow-up Questions
- ❓How do you store idempotency keys?
- ❓What about expiration of keys?
Advertisement