Finally got around to trying https://healthchecks.io/. Super elegant way to monitor cron jobs! Just append a curl to a job script, you can even pass the status code for some extra data.
Free Cron Job Monitoring - Healthchecks.io
Healthchecks.io alerts you when your cron jobs fail to run on time. Quick setup (no coding required), clean dashboard, affordable pricing.healthchecks.io