Cron use cases
Real recurring ops tasks, with a recommended cron expression, a worked crontab line, and the failure modes specific to each one — including where cron is the wrong tool for the job.
Scheduling database backups with cron
Nightly pg_dump/mysqldump with locking, retention, and a way to notice when it stops working.
Scheduling log rotation — and why you probably shouldn't use cron
Almost always logrotate's job, already wired into cron.daily — here's when to actually write your own.
Scheduling TLS certificate renewal
Certbot/acme.sh already schedule themselves — here's what's left for you to actually own.
Scheduling cache warming with cron
Pre-hit expensive or cold paths on a schedule so real users never pay the first-request cost.
Scheduling recurring report generation
Weekly or monthly report jobs, and the date-math bugs that make them wrong on specific days.
Scheduling data sync and ETL jobs with cron
Incremental sync/ETL runs with locking and idempotency — and where cron alone stops being enough.
Scheduling temp file and cache directory cleanup
Age-based deletion of stale temp/cache files — and why /tmp itself is probably already handled.
Scheduling health checks with cron
Cron's one-minute floor is too coarse for most health checks — here's what to use instead, and when cron is fine.
Scheduling email digests with cron
Daily or weekly digest sends, timezone-aware, with delivery failures treated as separate from generation.
Scheduling disk space monitoring with cron
A simple threshold check for one host — and where it stops scaling once you have a fleet.
Scheduling dependency and security scans with cron
Periodic scans of what's actually deployed — a backstop, not a replacement for CI-time scanning.