Recommended and mentioned products
Monitor your cron jobs and scheduled tasks, get notified when they fail.
freemium $20.0 / Monthly (100 checks, 10 team members)
Easy: Doing backups should be a frictionless process, otherwise you are tempted to skip it.
Backups for each zpool (daily backups to a different box with syncoid for most zpools and to the cloud with restic for some specific datasets).