Both me and a friend were building an app that ingests cryptocurrency data and stores it in a database for later analysis. The important part was that we wanted data at regular intervals. I'm not much into all this but this is what was asked of us. He wrote the app in Python; I wrote it in Elixir.
Turns out the API's of the various exchanges are (or were) atrocious. We'd get responses ranging from weird error codes to malformed data to timeouts. API's would randomly change. It was a mess.
My app just chugged along, a process per request per api endpoint. When some of these endpoints 'misbehaved' the others just kept going.
His app kept crashing, restart, and so one misbehaving endpoint would cause trouble for all the other ones. He had to add try...catch statements and fix the problems. I would just look at my logs, update the happy-path code, push it, and recompile() in the REPL.
I also have a bunch of personal projects chugging along on my VPS. They actively handle requests a few times per hour at least, by me, and they're doing fine despite the fact that I was quick about it and only wrote the 'happy path'. There's crashes and errors all over the place, and yet when one part crashes the rest just keeps going. It's been a rare occasion where the entire supervision tree failed and the app gave up.