Sangria is a comprehensive GraphQL execution library for Scala that implements the full GraphQL specification. It provides a type-safe domain-specific language for defining GraphQL schemas (ObjectType, InterfaceType, UnionType, EnumType, InputObjectType, ScalarType, etc.), a parser for GraphQL query and Schema Definition Language (SDL), a validation engine with over 20 built-in validation rules, and an asynchronous execution engine supporting deferred resolution, middleware, query reducers, and subscriptions. The library is modular with separate artifacts for AST representation, parsing, core execution, and macro-based schema derivation, and integrates with cats-effect, fs2, Monix, and various JSON marshalling libraries (spray-json, circe, play-json, etc.). The architecture is based on immutable case classes, visitor patterns for validation and AST traversal, typeclass-based marshalling, and a composable Action ADT for field resolution that supports values, futures, deferred values, and context updates. The codebase demonstrates strong engineering practices with extensive cross-compilation across Scala 2.12, 2.13, and 3.3, binary compatibility management via MiMa, automated CI/CD, and thorough test coverage including yaml-based scenario tests for validation and execution.