GraphQL Developer
GraphQL Developers design and implement flexible query APIs that allow clients to request exactly the data they need. Their English work involves explaining schema design decisions to frontend teams, justifying federation trade-offs in architecture reviews, documenting resolver behaviour, and discussing performance optimisations. This path covers the vocabulary for designing, communicating about, and debugging GraphQL APIs.
Topics covered
- Schema design
- Resolver patterns
- Federation & composition
- Performance: N+1 & DataLoader
- Subscriptions & real-time
- Security & authorisation
Vocabulary spotlight
4 terms every GraphQL Developer should know in English:
A function responsible for fetching the data for a single field in a GraphQL schema — every field that returns data has a resolver
"The user resolver makes one database query; the posts resolver makes one per user — that's the N+1 problem."
A performance anti-pattern where fetching a list of N items triggers N additional queries (one per item) instead of a single batched query
"Loading 100 users with their profile photos caused N+1: 1 query for users, 100 for photos."
A batching and caching utility that groups individual resolver calls within a single execution tick into a single batch request, solving the N+1 problem
"After adding DataLoader, 100 user requests became a single SQL IN clause instead of 100 queries."
An architecture where multiple GraphQL services each own a part of the unified schema and a gateway composes them into a single API for clients
"After federation, each domain team owns their subgraph schema independently — no more schema conflicts."
📚 Vocabulary Reference
Key terms organised by category for GraphQL Developers:
Schema & Types
Resolvers & Execution
Performance
Federation & Gateway
Recommended exercises
Real-world scenarios you'll practise
- Explaining the N+1 problem and DataLoader solution to a backend team implementing their first GraphQL API
- Writing an ADR justifying the choice of GraphQL over REST for a multi-client product
- Presenting a federation migration plan to an engineering director: benefits, risks, timeline
- Explaining field-level authorisation to a security reviewer: how resolver context enforces access control