12 API Concepts Every Backend Developer Must Know

Become the software engineer AI can't replace. 😳 👉 Join Amigoscode Academy: https://skool.com/amigoscode-academy Members hired at Apple, Amazon & Just Eat. These 12 API concepts come up in almost every backend interview, and in every real system you will ever build. I recorded this after one of my Academy students got grilled on them, and I wanted to make it click for everyone. In this video I walk through how a client talks to a server, and everything that makes that conversation fast, safe, and reliable: HTTP methods, status codes, REST, auth, rate limiting, pagination, caching, versioning, idempotency, and webhooks. Whether you build with Java, Spring Boot, Node, Python, or any other stack, these are the fundamentals that separate juniors from engineers who actually understand APIs. ⏱️ Chapters 0:00 Intro 0:07 Client & Server (request and response) 0:54 HTTP Methods (GET, POST, PUT, PATCH, DELETE) 2:06 Status Codes (2xx, 3xx, 4xx, 5xx) 3:20 REST explained 4:09 Anatomy of a Request (headers, query params, body) 5:23 Authentication vs Authorization 6:54 Rate Limiting (429 and Retry-After) 7:50 Pagination (offset vs cursor) 8:59 Caching (cache hit, miss, and CDNs) 9:40 Versioning (v1, v2, deprecation) 10:40 Idempotency (idempotency keys, like Stripe) 11:30 Webhooks (stop polling, get pushed) 12:26 Recap and interview tips Become the software engineer AI can't replace. 😳 👉 Join Amigoscode Academy: https://skool.com/amigoscode-academy Members hired at Apple, Amazon & Just Eat. Join my free community: https://skool.com/amigoscode Connect with me • LinkedIn:   / nelsonamigoscode   • Instagram:   / amigoscode   • Twitter/X: https://x.com/amigoscode • GitHub: https://github.com/amigoscode #java #javadeveloper #springboot #softwareengineering