“they switched MMPs they didn't implement any events on the new MMP and the old MMP was still connected to meta they still had campaigns optimizing on meta”

MMP migration without re-implementing events silently breaks all ad optimization

A real case: a company migrated their MMP, forgot to implement conversion events on the new one, and left Meta campaigns running against stale signals from the old one — undetected for almost a month. The failure was silent because the attribution and media teams were siloed. This is a must-audit checklist item before any MMP switch.