When activation dips after a redesign, product and growth often argue about UX while engineering quietly shipped a screen that never fires the activation event.
Start by comparing event volume against release notes and session recordings for the same cohort. If sessions exist but the event vanished, fix tracking before rewriting onboarding copy.
Only after the event fires reliably should you treat remaining drop-off as product friction. Otherwise every experiment measures noise.
A short instrumentation checklist in the release ritual prevents most of these ghosts — especially for Korean-language apps shipping rapid UI iterations.