📄️ How to Use This Guide
Why this guide exists, how it is structured, and how to prepare for a GraphQL technical interview so that you reason instead of reciting.
📄️ Core Concepts (10 Questions)
Ten foundational GraphQL questions with deep explanations of why each answer is correct, covering resolvers, operation types, N+1, introspection, interfaces, and more.
📄️ Schema Design (8 Questions)
Eight schema design questions covering nullability, pagination, userErrors, input types, deprecation, breaking changes, polymorphism, and naming conventions.
📄️ Performance and DataLoader (7 Questions)
Seven performance questions covering N+1 diagnosis, BatchMapping vs. DataLoader, JPA pitfalls, server-side caching, persisted queries, and benchmarking.
📄️ Security (7 Questions)
Seven security questions covering GraphQL-specific attack categories, depth attacks, alias amplification, operation safelisting, field-level authorization, logging, and the five-category threat taxonomy.
📄️ Federation (6 Questions)
Six federation questions covering why federation exists, entities and @key, the _entities query, query planning, federated authorization, and federation-specific breaking changes.
📄️ Production Operations (6 Questions)
Six production operations questions covering tracing setup, GraphQL-specific metrics, schema evolution in CI, depth vs. complexity vs. timeout, zero-downtime field migration, and incident runbooks.
📄️ System Design and Behavioral (8 Questions)
Four system design questions and four behavioral questions covering schema design for a streaming service, federation migration, p99 latency debugging, subscriptions, and reflective engineering judgment.