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

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

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

  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.