When designing a REST API, it's important to follow certain best practices to ensure that your API is efficient, scalable, and easy to use. Here are some key best practices for REST API design:

Use descriptive and meaningful resource URIs: URIs should represent resources and not actions. Use nouns instead of verbs in your URIs to make them self-explanatory. For example, instead of /getUsers, use /users.

Use HTTP methods correctly: Use HTTP methods (GET, POST, PUT, DELETE, etc.) appropriately and consistently. GET is used for retrieving resources, POST for creating resources, PUT for updating resources, and DELETE for deleting resources.

Version your API: Include a version number in your API URIs to allow for future updates without breaking existing clients. For example, /api/v1/users.

Use proper HTTP status codes: Return appropriate HTTP status codes with each response to indicate the success or failure of the request. For example, use 200 for a successful response, 400 for a bad request, and 404 for a resource not found.

Implement proper error handling: Return meaningful error messages and error codes when an error occurs. Include additional details in the response body to help clients understand the issue.

Implement pagination and filtering: When dealing with large collections of resources, provide mechanisms for pagination and filtering to allow clients to retrieve only the data they need.

Use query parameters for optional filtering and sorting: Use query parameters to allow clients to filter, sort, and search resources based on specific criteria. For example, /users?status=active&sort=name.

Ensure security: Implement proper authentication and authorization mechanisms to protect your API from unauthorized access. Use secure communication protocols (HTTPS) to encrypt data transmission.

Provide meaningful documentation: Create comprehensive documentation that describes each endpoint, their purpose, required parameters, and expected responses. Consider using tools like OpenAPI or Swagger to generate API documentation.

Handle versioning and backward compatibility: Plan for future changes by carefully managing versioning and maintaining backward compatibility whenever possible. Avoid making breaking changes that can disrupt existing clients.

Use consistent naming conventions: Follow consistent naming conventions for resources, endpoints, query parameters, and response structures. This improves the overall readability and understandability of your API.

Use proper data formats: Use appropriate data formats such as JSON or XML for request and response payloads. Consider supporting content negotiation to allow clients to request their preferred data format.

Implement proper caching mechanisms: Utilize HTTP caching mechanisms to improve API performance and reduce the load on your servers. Use cache headers such as "Cache-Control" and "ETag" to control caching behavior.

Provide rate limiting and throttling: Implement rate limiting and throttling mechanisms to prevent abuse and protect your API from excessive requests.

Consider HATEOAS (Hypermedia as the Engine of Application State): Design your API to include hyperlinks in responses, allowing clients to navigate the API and discover related resources dynamically.

By following these best practices, you can create a well-designed REST API that is easy to understand, maintain, and consume by clients.

Presented at Electronic Arts, Canada