Ping after the work, not before it

A cron that pings when it starts tells you the scheduler woke up. It does not tell you the job finished. Put the success ping at the end of the path that means the work happened.

If the process dies in the middle, that ping never arrives. The grace period expires and you get the alert. Use /fail on the error path when you want the alert now instead of at the deadline. A start ping is optional, and it does not move the deadline.