Cron scheduling with node-cron (with guard)

Periodic jobs are common (cleanup, digests, rollups), and it’s easy to accidentally run them on every instance in production. In local dev, in-process node-cron is fine. In production, I either run a dedicated worker or add a guard so only one instance schedules jobs (via an advisory lock or leader election). I keep cron tasks idempotent and fast, and I record a heartbeat in logs/metrics so it’s obvious when the scheduler dies. The core idea is that ‘cron’ is infrastructure—treat it as such, or you’ll run the same task N times and only notice when billing or data integrity goes sideways.