GraphQL Federation
GraphQL Federation is an architectural pattern and specification for building a single, unified GraphQL API (the federated gateway) that aggregates data from multiple, independently deployed GraphQL services (subgraphs). It enables teams to develop and scale GraphQL APIs in a distributed manner, where each service owns a portion of the overall schema and can be updated without coordinating with other teams. This approach helps manage complexity in large-scale applications by allowing modular development while presenting a cohesive API to clients.
Developers should use GraphQL Federation when building large, distributed systems where multiple teams need to own different domains (e.g., user management, product catalog, orders) but want to expose a single GraphQL endpoint to clients. It is ideal for microservices architectures, as it avoids the pitfalls of a monolithic GraphQL server and reduces coordination overhead. Specific use cases include e-commerce platforms with separate services for users, products, and payments, or enterprise applications with modular backend services that need unified data access.