Your cron job did not fail. It never ran.

Short summary

Scheduled jobs can fail silently when the job never starts at all — crond is masked, PATH differs, or the container was rescheduled. Standard exit-code monitoring cannot catch these because no process ran. The fix is a dead man's switch: the job pings a monitoring endpoint on start and completion, and the absence of a ping becomes the alert. The article provides production-ready bash wrapper code with trap-based failure reporting and series correlation for overlapping runs.

• •Silent cron failures happen when jobs never start, not when they fail
• •Exit-code monitoring cannot catch absence-of-event failures
• •Dead man's switch pattern: require good-news pings, alert on missing pings
• •Production bash wrapper with start/complete/fail pings and series correlation

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