Practice : GraphQL-first APIs

Purpose and Strategic Importance

GraphQL-first API design is a schema-driven approach where the API contract is defined before implementation begins. This promotes clear, flexible, and client-driven interfaces that improve integration, foster collaboration, and accelerate development.

By treating the schema as a shared source of truth, teams gain better visibility into system capabilities, reduce over-fetching or under-fetching of data, and streamline cross-team workflows for frontend and backend development.

Description of the Practice

  • A GraphQL schema is designed and agreed before implementation - similar to OpenAPI in REST.
  • Clients define their data needs via queries, and the server responds with precisely what’s requested.
  • Schema evolution is managed through tooling and clear deprecation strategies.
  • GraphQL supports strong typing, introspection, and auto-generated documentation.
  • Common frameworks include Apollo, GraphQL.js, Graphene, and Hasura.

How to Practise It (Playbook)

1. Getting Started

  • Define a shared GraphQL schema with product and engineering teams.
  • Use GraphQL SDL (Schema Definition Language) to model types, queries, and mutations.
  • Validate the schema with mock resolvers before implementation.
  • Enable developer tools like GraphiQL or Apollo Studio for collaboration.

2. Scaling and Maturing

  • Adopt schema registries and change validation to prevent breaking consumers.
  • Split schemas across domains using schema stitching or federation.
  • Include schema checks and contract tests in CI pipelines.
  • Instrument resolvers for observability, latency tracking, and usage analytics.
  • Use persisted queries or allowlisting to manage performance and security.

3. Team Behaviours to Encourage

  • Collaborate on schema design with consumers early in the lifecycle.
  • Treat schemas as versioned, shared artefacts across teams.
  • Use types to drive strong feedback loops between code and design.
  • Encourage feedback and usability improvements through schema reviews.

4. Watch Out For…

  • Overloading the schema with unrelated responsibilities or nested complexity.
  • Tight coupling between frontend and backend changes without proper abstraction.
  • Performance issues from inefficient resolvers or N+1 query patterns.
  • Lack of observability into resolver execution or schema usage.

5. Signals of Success

  • Consumers are empowered to get exactly the data they need - no more, no less.
  • APIs evolve safely and quickly with high confidence in schema stability.
  • Teams iterate faster through decoupled contracts and better tooling.
  • Developer experience improves with clear documentation and type safety.
  • Business features are unlocked through data flexibility and reuse.