Write-Audit-Publish with Iceberg Tables in Snowflake

It was a Tuesday afternoon when the analyst pinged me on Microsoft Teams: “Hey, the Total Portfolio numbers just jumped 40% overnight. Did we land a whale?” We hadn’t. What actually happened was more mundane and significantly more painful. A schema change in the source system introduced a currency conversion bug. Our pipeline dutifully loaded the corrupted data into production at 3 AM, the dashboards updated by 6 AM, and the Department Head opened her morning report to numbers that looked like champagne-worthy growth.