Used to not monitor at all, but after setting up crowdsec I got completeky into prometheus + grafana system resource and security monitiring on my dedicated hetzner server.
I also keep uptime kuma on another cheap vps to monitor the states of websites directly for issues and I have seted up watchtower to send ntfy notifications on updates so I can know an update is the one fucking everything up.
Recently also setup restuc backups so I made it so I also get backup health check logs as ntfy notifications on my phone, which really helps me keep everything runnig.
What I really need to also do is create prometheus/grafana alerts for additional things to get notifications on my phone for them also ( like when crowdsec starts to randomly not get any more acqusitions, so I have to restart it. Once passed over a week before I looked at grafana and caught that ).
Note: this is all a hoby, I also don't host anything at home out of a couple reasons, most important being internet and hardware is expensive af here so it's simply cheaper for me to play around with vps's and hetzner dedicated servers.
Yea, matrix is too much for that I need, an dhave seted up a mattermost server for my needs.
Planning to create a selfhosted team on it for the people of this communitty to talk real time about selfhosting and help each other fix issues in a more timelly and easier manner.