The sort of program that once set up, just ticks along without fuss or bother forever.
For me, as I’m replacing the vms today which I set up five years ago and haven’t needed to touch since;
- HAProxy
- KeepaliveD
Not easy to learn, but once they’re running, they both go on forever.


Systemd
*grabs popcorn*
Just it always makes you wait for ~3 min and shows: … wait for something to be Configured (25s / no limit). :-)
If that happens to you, maybe you should open the logs and figure out why it is happening.