# Maintain

Day-2 operations for a running Payerbox deployment.

| Page | What it covers |
|---|---|
| [Observability](observability.md) | Prometheus metrics, BALP audit logs, runbooks |
| [Upgrade](upgrade.md) | Bundle and per-image upgrade, breaking changes, rollback |

Event notifications (FHIR topic-based subscriptions) are documented under [Prior Auth / Event Notifications](../../prior-auth/event-notifications.md).