Delayed Job is a Ruby background-processing library designed to move long-running work out of the request cycle and into an asynchronous job queue. It was extracted from Shopify and is built around a database-backed jobs table rather than a separate queueing service. The system stores serialized Ruby objects that respond to a perform method, then workers pull and execute those jobs later. It supports priority, scheduled execution, retries, failure tracking, locking, and multiple workers across machines. ...