Every Node.js application that sends emails, processes images, generates PDFs, syncs data with third-party APIs, or runs any kind of deferred work eventually needs a job queue. Handling that work inline, inside an HTTP request handler, is a recipe for timeouts, dropped jobs, and unhappy users. That's where a Redis-backed queueing library comes in, and in the Node.js ecosystem two names dominate the conversation: Bull and BullMQ. Choosing between them is one of the most common architecture decisi...