Complete GraphQL Federation course: from GraphQL fundamentals (schema, resolvers, mutations) to enterprise supergraph architecture. Apollo Federation v2 (entities, @shareable, @inaccessible, @override), Apollo Router (Rust-based, query planning), schema composition and managed federation, subgraph development (TypeScript/Go/Rust), N+1 problem and DataLoader, GraphQL security (query depth, rate limiting, authZ), performance (caching, persisted queries, APQ), GraphQL Mesh and Hasura, REST → GraphQL Federation migration, monitoring via Apollo Studio/Grafbase. Practice: building a federated API from 4 microservices.