If you are ok with a Saas and if it's just scheduled jobs that you are monitoring, there are a number of monitoring tools where you tell when job completes (with a http request) and a missing ping (after a grace period) means that it failed.

I think https://deadmanssnitch.com/ may have been the original service for this.

https://healthchecks.io/ has a fairly generous free tier that I use now.

There are others that do the same thing Sentry, Uptime Robot, ...