Practice schemas, resolvers, queries, and GraphQL patterns with API design scenarios
Start Practicing NowMaster type definitions, queries, mutations, and subscriptions
Understand resolver functions, data loaders, and N+1 problems
Learn query optimization, caching, and batching strategies
Select GraphQL as your interview topic and customize the difficulty level
Answer realistic GraphQL interview questions in a simulated environment
Receive detailed feedback on your answers, including areas to improve
Monitor your improvement and identify strengths and weaknesses
Schema definition and type system
Queries, mutations, and subscriptions
Resolvers and data fetching
DataLoader and batching
Authentication and authorization
Apollo Server and client libraries
A: GraphQL allows clients to request exactly what they need (no over/under-fetching), single endpoint, strongly typed schema, real-time with subscriptions, introspection. REST has multiple endpoints, fixed responses, version management challenges. GraphQL is better for complex data requirements, mobile apps, multiple clients.
A: N+1 occurs when fetching a list plus related data: 1 query for list, N queries for each item's relations. Solution: DataLoader - batches and caches requests in single event loop tick. Example: fetching users and their posts becomes 2 queries (users, all posts) instead of N+1.
A: Query: read operations (GET in REST). Mutation: write operations (POST/PUT/DELETE). Subscription: real-time updates via WebSocket. Queries/mutations are synchronous request-response. Subscriptions maintain connection, push updates. Use queries for fetching, mutations for changes, subscriptions for live data.
A: Authentication: verify user before resolver execution (middleware, context). Authorization: check permissions in resolvers or directive-based (@auth). Context object shares auth across resolvers. Use shield or graphql-auth-directives. Handle at business logic layer, not GraphQL schema layer for flexibility.
Understand schema design and when to use types, interfaces, and unions
Master DataLoader pattern to prevent N+1 query problems
Practice with Apollo Server/Client or other popular GraphQL tools
Know how to implement pagination (offset vs cursor-based)
Understand caching strategies for GraphQL queries
Join thousands of developers who have improved their interview skills with Vibe Interviews
Start Your GraphQL Interview Practice