1. Sidekiq is a simple, efficient framework for background job processing in Ruby

  2. Super easy Rails servers. Configure any server to run Ruby on Rails servers in minutes and without hassle.

  3. Lambda is a cloud service that Amazon Web Services (AWS) provides, which allows developers to run serverless code.

  4. RabbitMQ is an open source message broker software.

  5. Resque is a Redis-backed Ruby library for creating background jobs, placing them on multiple queues, and processing them later.