REST and GraphQL are both widely used, but they solve different problems. Picking the right one—or a hybrid—depends on your clients, data shape, and team skills.
REST: Simplicity and Caching
REST uses standard HTTP verbs and resource-based URLs. It's easy to understand, cache-friendly (GET responses can be cached by CDNs and browsers), and works with every client. Version via URL or headers and keep resources coarse enough to avoid N+1 round-trips. REST shines when your domain maps cleanly to resources and clients need predictable, cacheable reads.
GraphQL: Flexibility and One Endpoint
GraphQL lets clients request exactly the fields they need in one request, reducing over-fetching and under-fetching. That's valuable for mobile and dynamic UIs. The trade-off: caching is harder (no HTTP caching by default), and you need to guard against expensive queries (depth limits, complexity analysis). Use GraphQL when clients have diverse data needs and you're willing to invest in schema design and tooling.
Design for Consistency
Whichever you choose, be consistent: clear naming, stable versioning, and good docs (OpenAPI for REST, schema introspection for GraphQL). Use pagination (cursor-based when possible), standard error formats, and rate limiting. A well-designed API is one your team and partners can rely on for years.