Save expensive calculation time using Rack::Attack, we will learn how to limit requests coming into our application. This gem not only limits requests, but can be used to blacklist or whitelist users as well.

Prevent unauthorized access to your application with Pundit; an authorization library for Ruby on Rails which restricts what resources a given user is allowed to access.

Add multi factor authentication to your existing authentication solution. This gives your users the option to increase the level of security to their account and help prevent unauthorized access.

Devise is a flexible authentication solution for Rails based on Warden. Learn how to add a stable authentication solution like Devise to your application.

Using ClamAV, scan files uploaded to your application for viruses. In the event of a virus learn how to gracefully handle the infected file and notify the user.