Two Bugs, Two Strangers, One Week: What Shipping Early Actually Buys You

A week ago I put a rough, honestly-a-bit-thin version of PulseWatch in front of real people for the first time. Within days, two different strangers — independently, unprompted — found two real gaps in it. Neither was catastrophic. Both were exactly the kind of thing you only find by watching someone else use the thing you built. This is the story of both, and the fixes. Bug one: the run that never ends This first bug came from a friend testing it on a real script. His question was simple: "What happens if start fires twice before end ?" Good question. At the time: nothing good. Here's why. PulseWatch works on two pings — a job calls /start when it begins and /success (or /fail ) when it's done. The server tracks whichever run is currently "open" for a monitor. The bug: if a job's process restarts mid-run — a crash-and-retry, a redeploy that catches it mid-flight, a scheduler firing twice — you get a second /start before the first run ever closes. The old run just sits there, open forever, an orphan with no ending. Worse, because the watchdog was still waiting on that run's expected finish time, it could fire a false "still running" alert for a run that was, for all practical purposes, dead and abandoned. The fix is a small rule with an outsized effect: a new /start supersedes whatever run is currently open. The old run gets marked superseded — a terminal, non-alerting status — and a fresh run begins clean. The watchdog was updated to treat superseded as a dead end: nothing to wait on, nothing to alert about, and it never shows up in a user's run history. It's not a failure and it's not a success. It's just "this run doesn't matter anymore, a newer one replaced it." The logic, roughly: def handle_start ( monitor ): open_run = monitor . get_open_run () if open_run is not None : open_run . status = " superseded " open_run . finished_at = now () new_run = Run ( monitor = monitor , status = " running " , started_at = now ()) db . session . add ( new_run ) db . session .