Part II - In this episode, we create performant links for adding, accepting/rejecting and removing friends for our social media application.

In this episode, we build our associations and organize our mathematical business logic.

In this episode, we continue the Trello clone by adding a collaborator invitation mechanism to join working on lists. We look at some tricky ActiveRecord relationships and various solutions.

Add an activity feed to your application with Public Activity.

In this episode we create a referral system with permanent links. Users can sign up with referral links which tracks the relationship between the referer and the person referred.