With systemd tooling, including mkosi, it is possible to build an OS image that fulfills all checkmarks a modern image-based OS should have, but with a standard off-the-shelf distribution!
This talk gives an overview for a possible workflow, including A/B updates and offline signed images and updates, in real-use. As a bonus, it is also self-replicating and uses as little configuration as possible, leveraging built-in systemd auto detection.