Every team that runs scheduled work eventually ships the same bug, and it does

not look like a bug. A cron job, a nightly workflow, a backup timer — something

that is supposed to run on a clock and quietly do useful work. To keep an eye on

it, someone adds a heartbeat: each time the job runs, it touches a file, pings a

status endpoint, or emits a "still alive" event. A sweep watches those beats and