Background job queues decouple time-consuming tasks — sending emails, processing images, generating reports — from the HTTP request cycle, keeping API responses fast and reliable. As the creator of CoreUI with 25 years of backend development experience, I’ve implemented job queues in Node.js applications where processing tasks synchronously caused request timeouts and poor user experience. BullMQ with Redis is the standard solution: jobs are enqueued instantly, workers process them asynchronously with retry, priority, and scheduling support. This architecture lets you return 202 Accepted immediately and process the work in the background.