What are some alternatives?
Faktory - a station where factors reside and trade; a building or set of buildings with facilities for manufacturing; the seat of some kind of production… See the full definition
Amazon SQS - Amazon Simple Queue Service is a fully managed message queuing service.
Que - Stop fighting over the AUX cord
RabbitMQ - RabbitMQ is an open source message broker software.
Sidekiq - Sidekiq is a simple, efficient framework for background job processing in Ruby
NServiceBus - NServiceBus is a service bus for .NET offering enterprise-grade scalability and reliability for your workflows and integrations.