Have you ever clicked "Save" on a document, and caused a coworker to lose hours of work? Or spent more time coordinating "Who has permission to edit" in Slack than you did actually writing the document? Google-Docs-style collaboration used to be nice to have. Now, it's expected. Companies like Quip and Coda have based their business on real-time collaboration features. Atom and Sublime Text have collaborative editing plugins. Even Confluence now supports collaborative editing! In this talk, you'll learn how to build a great collaborative experience, based on solid fundamental ideas.