Immutable Software Deploys Using ZFS Jails on FreeBSD / Conrad Research
｢ FreeBSD’s native support for ZFS snapshots and jails provides a powerful foundation for immutable deployments. By creating a new jail from a ZFS snapshot for every release, we get instant roll‑backs, zero‑downtime upgrades, and a clean, reproducible environment ｣
https://conradresearch.com/articles/immutable-software-deploy-zfs-jails