🕸️ GraphQL

Checklist

• Schema-first design: types, queries, mutations, subscriptions, input types, enums, interfaces/unions
• Resolvers and the execution model
• N+1 problem → DataLoader (batching + caching per request) ⭐
• Pagination (Relay connection spec / cursors)
• Errors (partial results), nullability design
• Security: query depth/complexity limits, persisted queries, authz in resolvers (field level)
• Caching challenges (POST, no HTTP cache) and solutions (persisted queries + GET, client caches)
• Federation (Apollo Federation / GraphQL Fusion) for microservices: awareness
• When NOT to use GraphQL

Implementations

• Java: Spring for GraphQL (@SchemaMapping, @BatchMapping)
• Go: gqlgen

🧪 Labs (🟢 warm-up → 🟡 core → 🔴 hard → ⚫ boss)

• 🟡 Spring for GraphQL: workflows → versions → runs → steps with @BatchMapping
• 🔴 Query depth/complexity limits + persisted queries
• ⚫ Subscriptions for run status vs SSE; compare them

🧠 Cognitive tasks

• Predict the number of SQL queries for a nested query with and without DataLoader

🛰️ Orbit integration

• The orbit-web UI data layer

Go deeper

🧩 Enterprise & DDD Patterns

Resources

• graphql.org/learn · Production Ready GraphQL (Giroux) · Spring for GraphQL docs