APIs & Integration

REST — Explained with Examples

REST (Representational State Transfer) is an architectural style for designing networked applications using stateless HTTP operations on resources.

What is an API — Simple Explanation with Examples

API stands for Application Programming Interface — a set of rules that allows software applications to communicate and share data with each other.

GraphQL — Explained with Examples

GraphQL is a query language for APIs that lets clients request exactly the data they need from a single endpoint using a strong type system.

gRPC — Explained with Examples

gRPC is a high-performance Remote Procedure Call framework by Google that uses Protocol Buffers and HTTP/2 for efficient service-to-service communication.

JWT — Explained with Examples

JWT (JSON Web Token) is a compact, URL-safe token format for securely transmitting claims between parties as a JSON object with optional signing.

Web Services Guide: SOAP, WSDL & Enterprise Integration

Master web services: SOAP protocol, WSDL contracts, XML-RPC, service-oriented architecture (SOA), and when to choose SOAP over REST or GraphQL for enterprise systems.

OAuth 2.0 — Explained with Examples

OAuth 2.0 is an authorization framework that enables third-party applications to obtain limited access to a user's resources without exposing credentials.

OpenID Connect — Explained with Examples

OpenID Connect (OIDC) is an identity layer built on top of OAuth 2.0 that verifies a user's identity and provides basic profile information.

CORS — Explained with Examples

CORS (Cross-Origin Resource Sharing) is a browser security mechanism that controls how web pages request resources from a different origin than their own.

WebSocket — Explained with Examples

WebSocket is a full-duplex communication protocol that provides persistent, bidirectional channels between client and server over a single TCP connection.

SSE — Explained with Examples

SSE (Server-Sent Events) is a one-way push technology that enables servers to stream data to clients over a single HTTP connection.

API Gateway — Explained with Examples

An API Gateway is a server that acts as a single entry point for client requests, routing them to appropriate microservices while handling cross-cutting concerns.

Rate Limiting — Explained with Examples

Rate limiting is a technique that controls how many requests a client can make to a server within a specific time window to prevent abuse and ensure fair usage.

HATEOAS — Explained with Examples

HATEOAS (Hypermedia as the Engine of Application State) is a REST constraint where API responses include links that guide clients to available actions.

Stripe Payment Integration: Complete Developer Guide

Learn Stripe payment integration: payment intents, checkout sessions, webhooks, refunds, subscription management, Stripe Elements, testing with test mode, and idempotency keys.

Twilio API: Sending SMS and Voice Messages

Learn Twilio API: send SMS and WhatsApp messages, make voice calls, use Verify API for phone verification, handle incoming messages via webhooks, error handling, and pricing.

SendGrid: Transactional Email API Guide

Learn SendGrid: send transactional emails via SMTP and REST API, dynamic templates, personalization, attachments, delivery tracking (opens, clicks), suppression management, and sender reputation.

OAuth 2.0: Complete Developer Guide with Examples

Learn OAuth 2.0: authorization code flow, implicit, client credentials, PKCE, access and refresh tokens, scopes, providers (Google, GitHub), libraries (Passport.js, Spring Security), and security.

API Versioning: Strategies and Best Practices

Learn API versioning strategies: URL versioning (/v1/), header versioning (Accept header), query parameter versioning, breaking vs non-breaking changes, deprecation policies, backward compatibility.

Webhooks — Event-Driven API Communication Guide

Webhooks are HTTP callbacks that enable real-time event-driven communication between web applications by sending automated notifications when specific events occur.

AsyncAPI — Event-Driven API Specification Guide

AsyncAPI is an open-source specification for describing event-driven APIs using a format similar to OpenAPI, enabling documentation and code generation for message-based systems.

Automated API Testing with Postman & Newman — Complete Guide

Learn automated API testing with Postman collections and Newman CLI — write tests, run in CI, generate reports, and catch regressions before they reach production.

API Documentation — OpenAPI/Swagger Guide

Learn to write API documentation with OpenAPI 3.1 and Swagger — design specifications, auto-generate docs, interactive playgrounds, and keep docs in sync with code.

API Pagination — Offset, Cursor & Keyset Patterns

Learn API pagination patterns — offset/limit, cursor-based, and keyset pagination — with implementation examples, trade-offs, and when to use each for scalable data access.

API Caching — HTTP Cache, CDN & ETag Guide

Learn API caching strategies — HTTP cache headers, CDN edge caching, ETags for conditional requests, and cache invalidation patterns for performant APIs.

API Error Handling Best Practices — Complete Guide

Learn API error handling best practices — consistent error formats, HTTP status codes, validation errors, retry strategies, and idempotency for reliable APIs.

API Auth — API Keys, JWT & OAuth2 Client Credentials

Learn API authentication methods — API keys for simple access, JWT for stateless sessions, and OAuth2 Client Credentials for machine-to-machine authorization.

GraphQL Subscriptions — Real-Time Guide with Examples

Learn GraphQL subscriptions for real-time data — WebSocket transport, subscription resolvers, event filters, and integration with message brokers like Redis Pub/Sub.

gRPC Streaming — Server & Bidirectional Guide

Learn gRPC streaming patterns — server-side streaming, client-side streaming, and bidirectional streaming with Protocol Buffers and HTTP/2.

OpenAPI Generator — Auto-Generate Client SDKs Guide

Learn to auto-generate API client SDKs with OpenAPI Generator — generate TypeScript, Python, Go clients from an OpenAPI spec and integrate them into your build pipeline.

API Versioning Strategies Deep Dive — Decision Guide

Compare API versioning strategies — URL path, header negotiation, query parameter, and no-versioning — with trade-offs, migration patterns, and a decision framework for choosing the right approach.