Backend APIs: REST, GraphQL, and gRPC

APIs connect frontends to data and services. REST, GraphQL, and gRPC each offer a different path. Choosing wisely helps you build scalable, maintainable systems without overengineering.

REST

REST is resource oriented and works smoothly with HTTP. It uses verbs like GET, POST, PUT, and DELETE. Its strengths are simplicity, predictable caching, and broad tool support. A typical pattern looks like: GET /users/123 POST /orders

Use REST when external clients need broad compatibility, easy caching, and clear resource modeling. It’s often the safest default for public APIs and for teams aiming for long-term stability.

GraphQL

GraphQL centers on client-driven data needs. A single endpoint answers a variety of questions, using a typed schema. Pros include precise data fetching and smoother evolution of the API. Cons can be a steeper learning curve and more complex tooling. A sample GraphQL query might be: query { user(id: “123”) { id name posts(limit: 5) { id title } } }

GraphQL shines when the frontend must fetch many related fields in one request, or when data requirements change often. It lets clients request exactly what they need, reducing overfetch.

gRPC

gRPC is a high-performance RPC framework built on HTTP/2 and Protocol Buffers. It offers strict contracts, fast serialization, streaming, and good support for internal microservices. An example service might define: service UserService { rpc GetUser(GetUserRequest) returns (User); } message GetUserRequest { string id = 1; } message User { string id = 1; string name = 2; }

Choose gRPC for low-latency internal calls, streaming data, or polyglot environments where performance matters. It is less common for public web APIs, but it can be ideal inside a service mesh.

Choosing a model

  • External-facing APIs with wide client support: REST is reliable and familiar.
  • Complex UI data needs or rapid API evolution: GraphQL can reduce overfetch and boost frontend productivity.
  • Internal services with performance needs: gRPC delivers speed and streaming capabilities.

Practical considerations

  • Versioning: REST favors explicit versioned paths; GraphQL uses deprecation with care; gRPC relies on backward-compatible schema changes.
  • Security: authentication through tokens generally works across all three, but each may need different tooling for auditing and rate limiting.
  • Tooling: choose formats and libraries you can support long term. GraphQL tooling often helps with schemas; gRPC needs proto tooling; REST benefits from a mature HTTP ecosystem.

Real-world teams often blend all three: a public REST API, a GraphQL facade for frontend data needs, and gRPC for internal services. This trio can share data models and stay coherent with a clear contract.

Key Takeaways

  • REST, GraphQL, and gRPC meet different needs; pick the right tool for the job.
  • GraphQL reduces overfetch, while REST emphasizes simplicity and caching.
  • gRPC excels in performance and streaming for internal services.