Context A GraphQL API resolving a list of posts with their authors triggers one database query per post to fetch the author, causing 101 queries for a list of 100 posts. The Problem Nested resolvers run independently per item, generating an N+1 query pattern that degrades performance at scale. Constraints Implement DataLoader to batch and cache author lookups per request. Instantiate a fresh DataLoader per request to prevent data leakage between users. Demonstrate the reduction from N+1 to 2 queries with a query log. Expected Deliverable A Node.js GraphQL API using DataLoader to batch database calls, reducing N+1 query patterns to batched queries with per-request cache isolation.