You stare at the empty test output. The DynamoDB table is full, the code compiles, and yet the integration test fails in a way unit tests never warned you about. This is the moment integration testing proves its worth—when your query logic meets the real shape, speed, and quirks of production-like data. And it’s the moment you either have clear runbooks to fix it fast, or you lose hours hunting in the dark.
Integration testing against DynamoDB is not optional when you care about correctness in distributed systems. A query that works in a mocked setup can break silently in production because of index mismatch, inconsistent reads, or evolving schema. Real integration tests surface these problems before they cost you. But they need to be fast enough to run often, precise enough to trust the results, and backed by reliable runbooks so action follows insight.
A strong DynamoDB query testing setup starts with a local or provisioned test database that mirrors your production configuration. IAM policies, table partition keys, sort keys, indexes, and TTL settings need to match production reality. Keep test data realistic: large enough to trigger pagination, varied enough to catch sorting and filtering edge cases, and consistent with the read patterns you expect to see live. Use Query and Scan in tests exactly as production does, including parameters for limit, index name, filter expressions, and consistent reads.