Rails scheduled job monitoring is easy to forget because scheduled work usually lives in the background. Your web app is up, requests are fine, the database is responding, and dashboards look green. Meanwhile, a nightly billing sync, cleanup task, email digest, or data import may have stopped running three days ago. That is the dangerous part: scheduled jobs often fail quietly. A Rails app can look completely healthy while important recurring work is missing. Users may not notice right away. You may not notice right away. Then suddenly invoices are wrong, trial expirations did not happen, reports are stale, or a queue is full of old data. This guide covers how Rails scheduled jobs fail, why logs are not enough, and how to use heartbeat monitoring to catch missed executions before they become production incidents. The problem Rails apps often rely on scheduled background work for things that are not directly tied to a web request.…