The role Firebase plays
Firebase commonly controls Authentication, Firestore, Storage, Hosting, and Cloud Functions. Its surrounding reliability depends on security rules, emulator/production differences, indexes, billing, and async function behavior, so the visible error may originate outside the file the AI last changed.
Specific failure patterns to inspect
For App Data Disappearing, common causes include temporary storage, destructive sync, row-ownership filter, environment reset. Generated implementations also tend to omit defensive error handling, version checks, idempotency, or a safe difference between public configuration and private credentials.
A safer diagnostic sequence
Preserve the current branch and exact error. Then record a sample ID; note the user role; check whether the record still exists. Follow one test request across the interface, server or provider, and durable data rather than making several speculative code changes.
Repair boundaries
The repair should change the narrowest contract that is actually broken. Broader refactoring is justified only when duplicated ownership or an unsafe architecture would otherwise let the failure return.
What to avoid
Do not restore over the live database without a backup or disable access rules broadly. Do not upgrade the entire Firebase stack during a contained incident unless version incompatibility is the proven cause.
What a complete handoff includes
The handoff identifies the root cause, affected code or settings, safe test case, deployment note, and any remaining follow-up. The repaired behavior should be protected by a repeatable check.