What runs underneath
Underneath it: containers and reverse-proxy routing on one tier, a traditional control-panel host on another, a CDN and web application firewall at the edge. Certificates renew themselves under a guardian that re-asserts them and starts complaining long before anything is close to expiring. Every site has its own uptime monitoring, with metrics, dashboards, and somewhere for an alert to actually go. And the self-healing responder and change protocol written up elsewhere on this site.
Backups are append-only to isolated offsite storage, with freshness, immutability and “the watchers are alive” as continuously asserted invariants rather than as a calendar reminder. Restore drills export metrics; a drill that stops running goes red.