• Background jobs run outside the main request-response cycle.
  • Used for tasks that are time-consuming or don’t need immediate response.
  • Examples: sending emails, processing images, generating reports.
  • Improves user experience by keeping the main app fast.
  • Usually managed by a job queue and a worker system.
  • Popular tools:
    • BullMQ (Node.js)
    • Sidekiq (Ruby)
    • Celery (Python)
  • Can be retried on failure and monitored separately.