Debugging

A per-request warehouse join was scanning 658.8 MB against a hard 953.7 MiB per-job ceiling, on a table growing with every new customer. I measured it, moved the join into the pipeline that already ran it, deleted the cache that was hiding the problem, then audited my own migration and found 79% of production rows never backfilled, plus 9,299 alerts that had never appeared in the product at all.

Corrected tens of thousands of corrupted production records (~33k in one case) with no maintenance window, using reusable CLI commands with dry-run, rollback files, batch auditing and event re-publishing, a "correction command" pattern the team then reused.

Turned a non-deterministic end-to-end suite (25 to 37 failures varying per run) into 302 passing with zero failures (8 pre-existing skips left untouched, and the consumer running), without adding a skip or weakening an assertion, and, in review, empirically proved that three of four proposed production changes were unnecessary.

In code review, caught a null-safety bug that would have crashed three production components, and fixed the defect class rather than the three instances, by proposing a shared data-layer helper to the PR's author instead of patching each render site myself; one of 310 pull requests I gave an explicit review verdict on that half (702 across four repositories between 2025-03 and 2026-08), measured from the Bitbucket API rather than recalled.