A foundational guide to GraphQL server internals covering the Schema Definition Language (SDL), the GraphQLSchema object, and resolver functions. Explains how each schema field maps to a resolver, how queries are executed breadth-first through the resolver chain, the four resolver arguments (root, args, context, info), and the N+1 problem with the DataLoader pattern. Compares GraphQL.js with graphql-tools, explaining that graphql-tools adds a convenience layer via makeExecutableSchema to bridge SDL declarations with resolver implementations, and briefly touches on graphene-js.
Table of contents
The GraphQL schema defines the server’s APIResolvers implement the APIGraphQL.js vs graphql-toolsConclusion1 Impression