Where Google's team put innovative effort into ChromeOS was in making it robust enough to be sold to the masses in the hundreds of millions of units, with no tech support. It's immutable, with image-based updates. It has two root partitions, one of which updates the other, so there's always a known good one to fall back to if an update should fail.

Vanilla OS also uses a two root partition system, called ABRoot, for its atomicity. The author should look into that, as it seems to be exactly what they're looking for.

This is a more fault-tolerant design than SUSE's MicroOS-based systems, which use the rather fragile Btrfs. It's also much simpler than the Fedora Atomic immutable systems, including offshoots such as Universal Blue, which use the Git-like — for which, read "fearsomely complex" — OSTree. For added entertainment, Fedora also defaults to Btrfs, with compression enabled. If you don't believe us about the problems of damaged Btrfs volumes, refer to the Btrfs documentation. We recommend taking the orange-highlighted Warning section very seriously indeed.

Stupid fearmongering about BTRFS (and OSTree, I presume). I selected an OpenSUSE distro precisely because it uses BTRFS and Snapper for automatic and transparent snapshots by default, which simplifies undoing most things that can break a system.