I wrote (or, ended up with a very much alpha but usable version) a monitoring system a while back and completely forgot about its existence.

But, it's still running and a few days ago I was building a docker imagine on a system with not that many resources and after about 5 minutes I started getting notifications about a high load!

Then, while I had forgotten about it again, yesterday, I suddenly started getting notifications about websites on my main application server going down.
Logged in and all was good again after restarting nginx.

Gotta say that it feels quite awesome to be notified of shit going wrong by something I wrote myself while I forgot about its existence 😊