REST vs. GraphQL Decision Framework

REST and GraphQL are not competitors. They are tools optimized for different access patterns. REST excels at resource-oriented access with predictable, cacheable responses — when the client knows what resources it needs and each resource has a natural URL. GraphQL excels at flexible, client-driven queries — when the client needs varying subsets of data across multiple resources and over-fetching or under-fetching with REST endpoints would be significant.

1. Choose REST When The API is resource-centric with well-defined entities. Caching is critical — REST leverages HTTP caching natively. The consumer base is large and diverse with varying technical sophistication. The API is public-facing and must be discoverable without specialized tooling. The team has deep REST experience and the operational model favors simplicity.
2. Choose GraphQL When Multiple clients need different subsets of the same data — mobile needs a compact payload, web needs a rich payload. The data model is deeply nested with many relationships. The frontend team wants to iterate on data requirements without backend changes. Over-fetching is a measurable performance problem. The team has the capacity to operate a GraphQL server and manage schema evolution.
3. Choose gRPC When Inter-service communication with strict performance requirements. The consumer and producer are both internal services with code generation tooling. Binary protocol efficiency matters — high throughput, low latency, streaming. The trade-off: gRPC is not browser-native and requires a gateway for web clients.