API Development & Integration

API development and integration encompasses the design, implementation, and consumption of programmatic interfaces following RESTful architectural constraints or GraphQL query language specifications. RESTful API development adheres to stateless client-server communication, resource-based URI structuring with proper HTTP verb semantics (GET, POST, PUT, PATCH, DELETE), HATEOAS principles for discoverability, and standardized status codes for response handling. GraphQL implementations provide typed schema definitions with queries, mutations, and subscriptions, enabling client-specified data requirements that eliminate over-fetching and under-fetching common in REST architectures. Authentication protocols implement OAuth 2.0 authorization frameworks with grant types (Authorization Code, Client Credentials, Implicit, Resource Owner Password) appropriate to use case, JWT (JSON Web Tokens) for stateless session management with RS256/HS256 signing algorithms, and API key mechanisms for server-to-server communication. Security hardening requires TLS 1.3 encryption, rate limiting with token bucket or sliding window algorithms, input validation and sanitization, SQL injection prevention through parameterized queries, and CORS (Cross-Origin Resource Sharing) configuration for browser-based consumers. API documentation adheres to OpenAPI Specification 3.1 (formerly Swagger) for REST APIs or GraphQL introspection for typed schema discovery, with interactive documentation through Swagger UI, Redoc, or GraphQL Playground. Versioning strategies include URI versioning (/v1/, /v2/), header-based versioning, or query parameter approaches, with deprecation policies providing adequate migration windows. Webhook implementations enable event-driven integrations with signature verification (HMAC-SHA256), exponential backoff retry logic, and idempotency key handling for duplicate request protection. Modern API architectures increasingly adopt gRPC for internal microservice communication leveraging Protocol Buffers for serialization efficiency, with GraphQL federation patterns for distributed schema composition across service boundaries.

Industry Insight