A server I'm running on a cheap VPS has downtimes as the hoster apparently switches the VPS off with no prior warning (crashes it) every so many weeks. (That hoster is Contabo, who does not have too good a reputation hereabouts.) They don't boot it up automatically, I have to do that myself.

The "keep it up" monitoring app on my Android smartphone helped me reduce the downtime by maybe a factor 5 or so.
https://f-droid.org/en/packages/net.ibbaa.keepitup/

@feditips