api-design-patterns

REST API design uses resource-based URLs, HTTP status codes, and consistent naming to create predictable endpoints. Apply REST conventions by organizing endpoints around nouns (resources), using GET/POST/PUT/DELETE for operations, returning appropriate status codes (200, 201, 400, 404), and structuring responses consistently across your Node.js, Flask, or FastAPI application.

Standardized error handling ensures clients receive predictable error responses. Define a consistent error response format with status codes, error messages, and details; implement error middleware in Node.js, Flask, or FastAPI; and document error scenarios for each endpoint so clients know what to expect and how to recover.

Pagination prevents large datasets from overwhelming responses. In REST, use limit/offset or cursor-based parameters in query strings. In GraphQL, use cursor-based pagination with DataLoader for efficient database queries. Both approaches improve performance and provide consistent navigation through results.

API versioning maintains backward compatibility while evolving your endpoints. Use URL-based versioning (v1, v2), header-based versioning, or accept parameter approaches to let clients opt into new behavior. Plan deprecation timelines and communicate changes to prevent unexpected client failures.

Secure APIs with authentication (API keys, JWT tokens, OAuth) and rate limiting to prevent abuse. Validate all inputs, use HTTPS, implement proper authorization checks, and follow security best practices specific to Node.js, Flask, or FastAPI frameworks to protect user data and prevent attacks.

GraphQL schema design defines your API's type system and query capabilities. Structure schemas around domain entities, implement resolvers that fetch data efficiently using DataLoader to batch requests, handle errors at resolver level, and document schema types so clients understand available queries and mutations.