[semi-extrinsic]

Also, Arch devs probably run Arch servers, and I'd not be surprised if some of those have uptimes in hundreds of days.

[Foxboron]

All Arch infra runs on Arch Linux. The infrastructure repository is all open.

https://git.archlinux.org/infrastructure.git/

Now, official infra doesn't reach hundreds of days. But personal systems might :)