databases

How HA Postgres and MariaDB are placed on this cluster, why the redundancy lives where it does, and how they are backed up.

Postgres is deployed: one CloudNativePG cluster in the postgres namespace, reconciled by the services layer, with per-application roles and databases declared beside it. MariaDB is still design only — the pages on replication, backups and the tradeoff describe both engines and the build follows them.