Experienced (3+ years)

API Design Interview Questions for Experienced Professionals

For developers with a few years of API Design under their belt, these 46 questions go beyond the basics into the architecture, performance and decision-making that experienced interviews focus on.

46Questions13Intermediate33Senior

46 API Design questions

  1. 1Explain Content Negotiation (Accept headers).Intermediate
  2. 2What is a Webhook?Intermediate
  3. 3Designing Error Responses in APIs.Intermediate
  4. 4What is HATEOAS?Intermediate
  5. 5How to design a Paginated API?Intermediate
  6. 6What is Rate Limiting and why is it necessary?Intermediate
  7. 7Explain OAuth2 and JWT for API security.Intermediate
  8. 8What is Idempotency in APIs?Intermediate
  9. 9How to handle API Versioning?Intermediate
  10. 10REST vs. GraphQL: When to use which?Intermediate
  11. 11API Design Interview Question 5 (Free)Intermediate
  12. 12API Design Interview Question 3 (Free)Senior
  13. 13API Design Interview Question 2 (Free)Intermediate
  14. 14Service Discovery and Load Balancing in API NetworksSenior
  15. 15Designing Search APIs with Elasticsearch/SolrSenior
  16. 16Security: Rate Limiting vs Throttling vs QuotasSenior
  17. 17API Testing Strategies: Contract Testing (Pact)Senior
  18. 18Idempotent API design in high-concurrency environmentsSenior
  19. 19Governance and Life Cycle Management of APIsSenior
  20. 20Designing an API for Mobile Clients (BFF Pattern)Senior
  21. 21Graceful Degradation and Priority-based SheddingSenior
  22. 22Shadow APIs and Zombie APIs: Risk MitigationSenior
  23. 23API Observability: Metrics, Logs, and Health ChecksSenior
  24. 24Designing long-running operations (Async Request-Reply)Senior
  25. 25Database Per Service vs. Shared Database in API designSenior
  26. 26API Performance: Payload compression and serialization (Protobuf)Senior
  27. 27Global Latency Optimization (Edge APIs and CDNs)Senior
  28. 28Evolutionary API Design: Avoiding Breaking ChangesSenior
  29. 29Designing Multi-tenant APIs and data isolationSenior
  30. 30CQRS (Command Query Responsibility Segregation) in API designSenior
  31. 31Handling Thundering Herd Problem in APIsSenior
  32. 32Designing an API for Third-party Ecosystems (SDKs/DevEx)Senior
  33. 33Zero-Trust Architecture in API SecuritySenior
  34. 34GraphQL Schema Stitching vs. FederationSenior
  35. 35Designing an Event-Driven API with Kafka/RabbitMQSenior
  36. 36API Caching Strategies: Client, Proxy, and Server-sideSenior
  37. 37Idempotency Keys and Distributed LockingSenior
  38. 38Distributed Tracing in complex API ecosystemsSenior
  39. 39gRPC vs REST for internal service communicationSenior
  40. 40Circuit Breaker Pattern in API designSenior
  41. 41Designing for 99.999% Availability in APIsSenior
  42. 42Microservices Communication: Synchronous vs. AsynchronousSenior
  43. 43Architecture of an API GatewaySenior
  44. 44API Design Advanced Interview Question 9Senior
  45. 45API Design Advanced Interview Question 8Intermediate
  46. 46API Design Advanced Interview Question 6Senior

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Frequently asked questions

Which API Design questions do experienced (3+ years) get asked?

This page collects 46 API Design interview questions aligned with experienced (3+ years), ranging across the difficulty levels that match that experience band.

How do I prepare for a API Design interview with my experience level?

Work through these questions in order, make sure you can explain each answer out loud, and pay attention to the real-world examples and follow-ups — interviewers at this level care as much about reasoning as the final answer.

Do the answers include code and examples?

Yes — answers include explanations, code examples where relevant, common mistakes to avoid and follow-up questions so you are ready for the full interview conversation.