As a mobile dev at YouTube I'd periodically scroll through crash reports associated with code I owned and the long tail/non-clustered stuff usually just made absolutely no sense and I always assumed at least some of it was random bit flips, dodgy hardware, etc.

I heard the same thing from a colleague who worked on a Dutch banking app, they were quite diligent in fixing logic bugs but said that once you fix all of those, the rest is space rays.

As an aside, Apple and Google's phone home crash reports is a really good system and it's one factor that makes mobile app development fun / interesting.

For the Mastodon Android app, I also sometimes see crashes that make no sense. For example, how about native crashes, on a thread that is created and run by the system, that only contains system libraries in its stack trace, and that never ran any of my code because the app doesn't contain any native libraries to begin with?

Unfortunately I've never looked at crashes this way when I worked at VKontakte because there were just too many crashes overall. That app had tens of millions of users so it crashed a lot in absolute numbers no matter what I did.