REST (Representational State Transfer) is an architectural style for designing networked applications. RESTful APIs use HTTP requests to perform CRUD operations on resources, making them accessible and manipulable over the web. RESTful APIs are stateless, meaning each request from the client must contain all necessary information for the server to fulfill it. Mastering REST principles allows engineers to build scalable, secure, and efficient APIs that follow widely adopted conventions.
At this level, engineers understand the basics of REST and can work with simple RESTful APIs.
- HTTP Methods: Basic knowledge of HTTP methods (GET, POST, PUT, DELETE) and their typical uses in RESTful services.
- CRUD Operations: Familiarity with performing Create, Read, Update, and Delete (CRUD) operations in a REST context.
- Basic Request-Response Cycle: Understanding of how a client sends a request and the server responds, with a limited grasp of HTTP status codes.
- Stateless Communication: Awareness that RESTful communication is stateless, meaning each request from a client to the server must contain all information needed to process it.
Engineers can use HTTP methods for basic CRUD operations, handle simple request-response cycles, and understand the principles of stateless communication.
At this level, engineers can work with more complex RESTful APIs and have a solid understanding of REST design principles.
- HTTP Status Codes: Familiarity with a broad set of HTTP status codes (e.g., 201 Created, 400 Bad Request, 401 Unauthorized, 403 Forbidden) and their correct usage.
- RESTful Resource Design: Ability to design RESTful resources aligned with API conventions, using proper naming conventions (e.g., plural nouns for collections,
/users). - URI Design: Understanding best practices for URI design, including hierarchical resource structures, query parameters, and the difference between path parameters and query strings.
- Headers and Caching: Knowledge of HTTP headers (e.g., Content-Type, Authorization) and basic caching mechanisms (e.g., ETag, Cache-Control).
Engineers can design RESTful resources, use appropriate status codes, structure URIs, and leverage HTTP headers and caching for efficient data handling.
At this advanced level, engineers are proficient in designing robust RESTful APIs, optimizing for scalability and security.
- API Versioning: Knowledge of API versioning strategies (e.g., URI versioning, header-based versioning) and when to apply each.
- Pagination and Filtering: Ability to design APIs with pagination and filtering for efficient handling of large datasets.
- Rate Limiting and Security: Familiarity with rate limiting, throttling techniques, and security practices like API key management and token-based authentication.
- Error Handling and Response Structure: Proficiency in designing consistent error responses, using structured error codes, and providing meaningful error details in responses.
Engineers can build scalable and secure APIs with versioning, pagination, rate limiting, and structured error handling to improve user experience and resource management.
An expert in REST has deep knowledge of REST principles and can design complex, enterprise-grade APIs that prioritize scalability, security, and maintainability.
- HATEOAS (Hypermedia as the Engine of Application State): Knowledge of implementing hypermedia controls within responses to guide client interactions dynamically.
- Advanced Security and Compliance: Proficiency in securing REST APIs using OAuth2, JWT, and compliance practices for standards like GDPR and CORS.
- API Documentation and Testing: Experience with documenting APIs using tools like OpenAPI/Swagger, Postman, and setting up automated testing for endpoints.
- Performance Optimization: Expertise in optimizing API performance through caching, response compression, payload minimization, and handling resource-intensive requests.
Engineers can architect complex REST APIs with HATEOAS, advanced security, automated testing, and performance optimizations suitable for enterprise applications.