> I'd also argue you shouldn't be doing side-effects like that in an init without a lot of care as well.

I learned this the hard way. I wrote a GenServer that does some periodic database cleanup (maybe not the best solution), and I naively wrote the init function to immediately do the first cleanup on startup. Then I discovered a case off the happy path where the cleanup was failing due to a constraint violation, and the failing init brought down the whole application (edit: while someone was trying to use it, of course).