Building Modern APIs: REST, GraphQL, and gRPC

Choosing an API style depends on what you build. REST, GraphQL, and gRPC each fit different goals. Understanding their strengths helps you design interfaces that last. The right mix can speed development and improve the experience for developers and users alike.

REST treats data as resources. Use clear nouns in the URL, such as /users or /orders. Use HTTP methods to act on resources: GET, POST, PUT, DELETE. REST calls are stateless, cache-friendly, and easy to test in the browser. For public APIs, REST often remains the simplest path.

GraphQL lets clients ask for exactly the fields they need. There is one endpoint and a strongly typed schema. The server validates queries and resolves data from backend services. Clients avoid over-fetching, and new fields can appear without changing the API surface. Drawbacks include a steeper learning curve and caching considerations.

gRPC is a fast, contract-based option for internal services. It uses Protocol Buffers and HTTP/2, which enable streaming and low latency. It shines in microservice architectures and data pipelines. Browser support is limited, so gRPC is usually used for server-to-server calls, while REST or GraphQL handles public clients.

When to choose each style? REST for broad compatibility and public APIs; GraphQL for flexible client data needs; gRPC for high-performance service communication and streaming. Many teams mix styles: REST outward, GraphQL for mobile apps, gRPC between services.

  • Design stable contracts with clear versioning or deprecation policies
  • Document schemas and error shapes
  • Plan authentication and authorization across APIs
  • Consider pagination, caching, and retry strategies
  • Use appropriate tooling: OpenAPI for REST, GraphQL tooling, protobuf for gRPC

This blended approach helps teams stay fast while keeping APIs maintainable.

Key Takeaways

  • REST remains simple and widely supported.
  • GraphQL offers precise data fetching and fewer round-trips.
  • gRPC provides speed and strong contracts for internal calls.
  • A thoughtful mix of REST, GraphQL, and gRPC fits many apps.
  • Plan versioning, authentication, and observability from the start.