This document discusses using Slack to improve communication for an online computer science course with 67 students. It notes the course currently uses multiple channels like announcements, discussion forums, email, and Zoom chat which causes information to get lost. Slack is proposed as a single place for real-time, rich communication that is customizable and GDPR compliant. The document reviews literature on the importance of online communities for motivation and preventing isolation. It introduces Garrison, Anderson, and Archer's Community of Inquiry framework and discusses building social presence among students to encourage engagement. Sections then describe how Slack was introduced to the class and feedback which found it very or essentially useful.