Mastering REST API Design & Best Practices

"Design the backend for Twitter." Reciting HTTP verbs won't get you through that whiteboard session. In this deep dive we build a complete, staff-level blueprint for REST API design: the reasoning behind every rule, the trade-offs interviewers probe, and the patterns that keep large systems evolving safely.You'll learn:- Fielding's six REST constraints, and why statelessness unlocks horizontal scaling- The Richardson Maturity Model, from the "swamp of POX" to HATEOAS- URI design: stable identifiers, shallow nesting, filtering and sparse fieldsets- Safety and idempotency, PUT vs PATCH, and JSON Merge Patch vs JSON Patch- Status codes that show polish: 201 + Location, 409 Conflict, 410 Gone, 422- Offset vs cursor pagination- Versioning, breaking changes, tolerant readers and the expand-contract pattern- Deprecation headers, RFC 7807 problem details and trace IDs- OAuth 2.0, API keys, JWTs and mutual TLS- Rate limiting: fixed window, sliding log, token bucket and leaky bucket- ETags, Cache-Control, and 202 Accepted for long-running jobs- OpenAPI and consumer-driven contract testing with PactChapters00:00 The whiteboard challenge01:35 An API as a city02:20 Fielding's six constraints03:28 Code on demand04:38 Statelessness and scaling07:44 The layered system09:21 The Richardson Maturity Model12:29 HATEOAS and server-driven state15:13 Pragmatic hypermedia15:59 URI design rules17:30 Stable identifiers18:38 Nesting vs flattening20:12 Query parameters20:59 Safety and idempotency22:54 PUT vs PATCH25:39 JSON Merge Patch vs JSON Patch27:39 201, 202 and 20428:25 409 Conflict and optimistic locking30:19 410 Gone31:07 400 vs 42231:54 Response envelopes32:41 Offset pagination34:39 Cursor pagination36:11 API versioning38:55 Breaking vs non-breaking changes40:30 Tolerant readers41:40 The expand-contract pattern44:46 Deprecation and Sunset headers45:52 RFC 7807 problem details46:41 Trace IDs47:27 Never leak internals48:14 Returning all validation errors49:24 OAuth 2.0 and API keys51:25 JWTs and mutual TLS52:57 Rate-limiting algorithms56:29 429 and Retry-After57:15 ETags and Cache-Control1:01:11 Async jobs with 202 Accepted1:03:58 OpenAPI1:05:30 Consumer-driven contracts with Pact1:08:39 Recap: API design is empathy#RESTAPI #APIDesign #SystemDesign #BackendEngineering #SoftwareArchitecture #InterviewPrepInterview Prep Podcast