What is cron job?
Quick definition
A scheduled task that automatically executes at specified times or intervals on a server or system, running scripts or commands without manual intervention.
A cron job is a time-based job scheduler in Unix-like operating systems that executes scripts, commands, or applications at predefined intervals. It uses cron expressions (crontab syntax) to define the exact timing: minute, hour, day of month, month, and day of week. This enables automation of repetitive tasks like backups, data synchronization, log rotation, and API calls without requiring manual execution or continuous process monitoring.
Cron jobs are essential for DevOps, system administration, and AI workflows. They integrate with deployment pipelines, data processing systems, and AI agents that need to trigger actions at specific times. In the context of Kanban boards and project management systems, cron jobs can automate routine tasks such as archiving closed cards, updating status fields, sending notifications, or syncing external data. For AI agents and MCP servers, cron jobs enable scheduled data fetching, model retraining triggers, and periodic health checks without human intervention.
Example
How it shows up in practice
0 2 * * * /usr/local/bin/backup.sh – runs daily at 2:00 AM; */15 * * * * /opt/sync-agent.py – runs every 15 minutes
Frequently asked questions
How do cron jobs differ from webhooks?
Cron jobs are time-triggered and push-based (initiating actions at scheduled times), while webhooks are event-triggered and pull-based (responding to external events). Use cron jobs for periodic tasks and webhooks for real-time event responses.
Can cron jobs be used in AI workflows?
Yes. Cron jobs schedule periodic AI agent executions, trigger data pipelines, refresh model parameters, or collect analytics at specific intervals without manual intervention.
What happens if a cron job fails silently?
Cron typically logs output to system mail or syslog. Monitor cron job execution by redirecting output to log files and setting up alerts for failures.
How do you define cron job timing?
Use crontab syntax: five fields represent minute (0-59), hour (0-23), day (1-31), month (1-12), and weekday (0-7). Use * for any value and / for intervals.