2026

GraphQL Interview Questions 2026

A current, 2026 snapshot of the GraphQL interview questions worth knowing — kept up to date as frameworks and best practices evolve, so you prepare with what companies are actually asking in 2026.

60Questions14Beginner13Intermediate33Senior

60 GraphQL questions

  1. 1What is the Context object in GraphQL resolvers?Intermediate
  2. 2What is Introspection in GraphQL?Intermediate
  3. 3How does error handling work in GraphQL?Intermediate
  4. 4What are GraphQL Subscriptions?Intermediate
  5. 5What are Input Object Types?Intermediate
  6. 6Explain Interfaces and Unions in GraphQL.Intermediate
  7. 7What are Directives in GraphQL?Intermediate
  8. 8How and why do you use Variables in GraphQL?Intermediate
  9. 9What is a GraphQL Fragment?Intermediate
  10. 10What are Aliases in GraphQL?Intermediate
  11. 11What does non-nullable (required) mean in a GraphQL schema?Beginner
  12. 12What is GraphiQL (or GraphQL Playground)?Beginner
  13. 13How do you pass arguments to a GraphQL field?Beginner
  14. 14What is a Resolver in GraphQL?Beginner
  15. 15What are the default Scalar types in GraphQL?Beginner
  16. 16What is a Mutation in GraphQL?Beginner
  17. 17What is a Query in GraphQL?Beginner
  18. 18What is the GraphQL Schema Definition Language (SDL)?Beginner
  19. 19What are the main differences between GraphQL and REST?Beginner
  20. 20What is GraphQL?Beginner
  21. 21GraphQL Interview Question 2 (Free)Intermediate
  22. 22GraphQL Interview Question 5 (Free)Intermediate
  23. 23GraphQL Interview Question 4 (Free)Beginner
  24. 24GraphQL Interview Question 3 (Free)Senior
  25. 25GraphQL Interview Question 1 (Free)Beginner
  26. 26How to manage Database Transactions across GraphQL Resolvers?Senior
  27. 27What are GraphQL Connections and Edges?Senior
  28. 28Explain the concept of Schema-First vs Code-First development.Senior
  29. 29How do you test GraphQL APIs effectively?Senior
  30. 30What is the purpose of the `graphql` package's Execution Phase?Senior
  31. 31How do you implement Mocking in a GraphQL Server?Senior
  32. 32What is the `@client` directive in Apollo Client?Senior
  33. 33How does Tracing and Observability work in GraphQL?Senior
  34. 34What is Schema Stitching vs Schema Federation in depth?Senior
  35. 35Discuss Performance Implications of Abstract Types (Unions/Interfaces).Senior
  36. 36How do you manage Nullability Design in enterprise schemas?Senior
  37. 37What is a Schema Registry and how does it assist CI/CD?Senior
  38. 38How does Batching work at the network level in GraphQL?Senior
  39. 39Explain the implications of GraphQL over HTTP (GET vs POST).Senior
  40. 40What are the challenges of scaling Subscriptions in a distributed architecture?Senior
  41. 41How does GraphQL versioning work? Why is there no 'v1/v2'?Senior
  42. 42How to handle File Uploads in GraphQL?Senior
  43. 43How do you implement Custom Schema Directives?Senior
  44. 44What is 'Resolver Lookahead' and how does it optimize database queries?Senior
  45. 45How does the Abstract Syntax Tree (AST) work in GraphQL?Senior
  46. 46What are Optimistic UI Updates in GraphQL clients?Senior
  47. 47Explain Apollo Client's Normalized Cache.Senior
  48. 48How do you implement caching at the CDN level with GraphQL?Senior
  49. 49What are Automatic Persisted Queries (APQ)?Senior
  50. 50How do you secure a GraphQL API against malicious or overly complex queries?Senior
  51. 51What is Schema Stitching vs Apollo Federation?Senior
  52. 52How do you implement Authorization at the resolver level?Senior
  53. 53How does Cursor-based Pagination work and why is it preferred over Offset-based?Senior
  54. 54Explain the concept and mechanics of DataLoader.Senior
  55. 55What is the N+1 problem in GraphQL and how do you solve it?Senior
  56. 56GraphQL Advanced Interview Question 10Beginner
  57. 57GraphQL Advanced Interview Question 9Senior
  58. 58GraphQL Advanced Interview Question 8Intermediate
  59. 59GraphQL Advanced Interview Question 7Beginner
  60. 60GraphQL Advanced Interview Question 6Senior

Explore more GraphQL interview questions

By Level

By Experience

Or browse all GraphQL interview questions.

Frequently asked questions

Are these GraphQL interview questions up to date for 2026?

Yes. This page reflects 60 GraphQL interview questions kept current with today's frameworks, tooling and interview trends, with each answer maintained and dated.

What GraphQL topics should I focus on in 2026?

Prioritise the fundamentals plus the modern patterns interviewers ask about now. Each question here includes a detailed answer, code example and common mistakes so you can target the highest-impact areas.

Are these questions free?

You can read the question and a short answer for free. A subscription unlocks the full detailed explanation, real-world example, common mistakes and follow-up questions for each one.