Que is a high-performance job queue for Ruby that stores jobs in PostgreSQL and uses advisory locks for efficient, concurrent processing.

It integrates nicely with Rails and ActiveJob, enabling transactional job enqueueing and predictable failure handling.

Setup involves adding the gem, running migrations to create the job table, and starting the worker process that executes queued jobs. Que supports Rails 6, 7 and 8 on Ruby 3+ and is actively maintained.

Its strengths are performance, reliability, and a lean codebase that leverages Postgres primitives; its weaknesses are a smaller ecosystem and fewer out-of-the-box features compared to Sidekiq. Alternatives include GoodJob for a batteries-included Postgres approach or Sidekiq for Redis-based scaling.