Tracing IDs across batch uploads and synchronous APIs

Integration paths rarely fit a single style. A wholesale partner may drop CSV bundles overnight while customer service hits a REST API by day. Tracing IDs need to survive both.

We show how to embed correlation IDs in file metadata rows and echo them into API responses once records graduate to online validation. Participants practice propagating IDs through a mock ETL and into support tooling so agents stop opening three systems to answer one ticket.

Labs emphasize honest limitations. When vendors strip headers or rename columns, the memo documents manual reconciliation windows instead of pretending full automation.

Capstone reviewers look for explicit rollback: what happens when half a file parses? We expect participants to describe partial failure UX, not just happy-path diagrams.