API Design & Communication

Building a great API is about establishing a rock-solid, scalable contract between your frontend clients, your backend microservices, and external third parties.

In this module, we move beyond basic HTTP to explore the entire spectrum of modern communication protocols, architectural styles, and the hidden scaling challenges of real-time systems.

What's Inside?

• HTTP Fundamentals: The foundational transport layer of the web.
• REST Fundamentals: History, constraints, and the myth of HATEOAS.
• GraphQL: Solving over-fetching, and handling the dreaded N+1 database problem.
• SOAP APIs: The legacy XML giant and WSDL contracts.
• Modern RPC (gRPC & tRPC): High-performance binary protocols and end-to-end type safety.
• Real-Time APIs (Polling & SSE): Evolving from Short Polling to native Server-Sent Events.
• WebSockets & Scaling: The nightmare of scaling stateful TCP connections across load balancers.
• Webhooks & Events: Inverting the request model and securing payloads with HMAC.
• API Security & OAuth 2.0: Securing endpoints with stateless JWTs and delegated authorization.
• Versioning & Pagination: Offset vs Cursor pagination and preventing breaking changes.

"APIs should be easy to use and hard to misuse."