We built a full-featured chat application from scratch using Twilio Programmable Chat and Ruby on Rails. We started by creating a new Rails application, adding a default action to serve our chat interface, and styling it with Bourbon and Bitters. Next, we created users and authenticated them using the Clearance gem, then generated a secure token for each user to communicate with our Programmable Chat instance. We integrated Twilio's JavaScript library to create a channel and join it if necessary. We also added an addMessage method to display messages in the chat interface, sending and receiving messages from our Programmable Chat instance, and binding events to act on incoming messages. With this basic implementation, we can now build upon it by adding more features such as private channels or usernames for users.