Nothing in particular: I believe HiFiBerryOS does some stuff under the hood to minimize unnecessary writes, but I didn't look too closely into it. The also provide shutdown and reboot buttons via their Web UI, which I greatly appreciate (and presumably help avoid any corruption that can happen when just yanking the power).

For the other Pis I use, I see corrupted SDs roughly once every 18 months. I replaced a couple of repeat offenders with new cards (from a different vendor) a while back and things seem to have stabilized, so my (lay) guess is that some cards are just more finnicky on the Pi than others.

I suspect that most of the SD card corruption could be remedied by an overlay fs.

The way I did this before - with excellent results - was to run openwrt on a pi, which is designed well in this respect. There is no continuous logging or other nonsense to corrupt the filesystem when you lose power.

I recently found out raspbian now allows you to do a (read-only) overlay filesystem:

  $ sudo raspi-config
  4 Performance Options -->

  P3 Overlay File System Enable/disable read-only file system

Is it entirely read-only, or would I be able to still write when I want to? For example, Octoprint isn’t much use if I can’t upload models to print.

My problems weren’t due to file system corruption. I think the cards wear out quickly due to writing.