Web App API Development

A well-designed REST API is intuitive, consistent, and predictable. We follow resource-oriented design principles — nouns for URLs, HTTP verbs for actions, proper status codes for responses, and HATEOAS links for discoverability. Developers integrating with your API should be able to guess the endpoint for a new resource without reading the documentation.

Our RESTful APIs include pagination with cursor-based navigation for large result sets, filtering with query parameters for flexible data retrieval, field selection for bandwidth optimization, and bulk operation endpoints for batch processing. These patterns reduce the number of API calls clients need to make, improving both performance and developer experience.

Versioning is built in from the start. When breaking changes are necessary, we introduce a new API version while maintaining the old one. Deprecation timelines give consumers adequate notice to migrate, and automated compatibility tests ensure old versions continue to function correctly.

GraphQL solves the over-fetching and under-fetching problems that plague REST APIs in complex applications. Clients request exactly the data they need in a single query, reducing payload sizes and eliminating the need for multiple round trips. We implement GraphQL APIs with efficient resolvers, DataLoader for batching, and query complexity analysis to prevent abuse.

Our GraphQL implementations include real-time subscriptions for live data, schema stitching for composing multiple services into a single API, and code generation that produces type-safe client libraries from the schema. The schema serves as a contract between frontend and backend, catching integration errors at build time.

Every API endpoint is protected by authentication and authorization. We implement JWT-based authentication with refresh token rotation, OAuth 2.0 for third-party integrations, and API key management for machine-to-machine communication. Authorization checks verify not just identity but also resource-level permissions before returning data.

Security layers include rate limiting per endpoint and per client, input validation that rejects malformed requests before they reach business logic, CORS configuration that restricts cross-origin access, and request logging for audit trails and forensics.

We follow OWASP API Security Top 10 guidelines and conduct security reviews on every API before it goes live. Penetration testing against the API surface identifies vulnerabilities that automated tools miss.

API documentation is generated from code annotations, ensuring it is always accurate and up to date. Interactive documentation powered by Swagger UI or GraphQL Playground lets developers explore endpoints, submit test requests, and see response formats without writing any code.

We provide SDK libraries for common languages when your API serves external developers. These SDKs handle authentication, pagination, error handling, and retry logic, reducing integration time from days to hours. Webhook documentation includes payload schemas, delivery guarantees, and testing tools.