Background Job Queue Design

Design a background job and queue system for {{use_case}} in {{stack}}. Cover what should be async versus synchronous, the queue and worker setup, job idempotency and retries with backoff, handling failures and dead-letter jobs, ordering and concurrency, prioritization, monitoring and visibility, and how to handle a job that gets stuck or runs too long. Make jobs reliable so work is neither lost nor duplicated, and note the failure modes that cause silent data issues and how to guard against them.