Mine is in the picture: 1544 days and counting!
It’s an EC2 nano instance that’s used only as a monitor for a few services that are running inside my VPN. It has served me well over all these years!
EDIT: before everyone starts screaming about “security”:
It’s not internet facing and no port is opened, all it does is fire up a notification if/when something doesn’t reply.
Even in the unlikely scenario that someone gain access to it that means that my VPN is already compromised, and I’ve got bigger problems to worry about.
I don’t know it depends on the patches really I have automatic updates so I guess a few months would probably be the longest between kernel patches