What is Delayed::Job?
Database based asynchronous priority queue system -- Extracted from Shopify - collectiveidea/delayed_job
Delayed::Job (or DJ) encapsulates the common pattern of asynchronously executing longer tasks in the background. It is a direct extraction from Shopify where the job table is responsible for a multitude of core tasks. Amongst those tasks are: sending massive newsletters image resizing http downloads updating smart collections updating solr, our search server, after product changes batch imports spam checks