Building GraphQL Server

Overview

Build production-ready GraphQL servers with SDL-first or code-first schema design, efficient resolver implementations with DataLoader batching, real-time subscriptions via WebSocket, and field-level authorization. Support Apollo Server, Yoga, Mercurius, and Strawberry across Node.js and Python runtimes.

Prerequisites

• Node.js 18+ with Apollo Server/Yoga/Mercurius, or Python 3.10+ with Strawberry/Ariadne
• Database with ORM (Prisma, TypeORM, SQLAlchemy) for resolver data sources
• Redis for subscription pub/sub and DataLoader caching (production deployments)
• GraphQL client for testing: GraphiQL, Apollo Studio, or Insomnia
• graphql-codegen for TypeScript type generation from schema (recommended)

Instructions

1. Examine existing data models, database schemas, and business requirements using Read and Glob to determine the entity graph and relationship structure.
2. Design the GraphQL schema with type definitions, including Query, Mutation, and Subscription root types, input types for mutations, and connection types for paginated lists.
3. Implement resolvers for each field, using DataLoader to batch and deduplicate database queries for nested relationships (N+1 query prevention).
4. Add input validation on mutation arguments using custom scalars (DateTime, Email, URL) and directive-based validation (@constraint(minLength: 1, maxLength: 255)).