Apollo Federation enables distributed GraphQL architecture where multiple services contribute to a unified schema, supporting microservices patterns and team autonomy. As the creator of CoreUI, a widely used open-source UI library, I’ve implemented federated GraphQL architectures in enterprise systems throughout my 12 years of backend development since 2014. The most scalable approach is creating subgraph services with entity resolution and a gateway that composes the federated schema. This method provides service independence, type safety across services, and seamless schema composition without manual schema stitching.