Background Jobs — Notes

Functional

• Enqueue jobs from app.
• Workers consume + execute.
• Retries, delayed jobs, scheduled jobs.
• DLQ + replay UI.

Non-functional

• Tens of millions of jobs/day common.
• Per-job latency depends entirely on workload.

Trade-offs

• Redis-backed (Sidekiq) = fast, ephemeral; DB-backed = durable.
• Per-app queues vs shared: isolate noisy neighbors.
• Autoscaling based on queue depth + processing time.

Refs

• Sidekiq / Celery / RQ / Resque docs.
• "Latency sensitive background jobs" Shopify blog.
• AWS SQS + Lambda patterns.