Slack is rolling out its biggest ever redesign. It is all centered around major changes to the sidebar. Senior exec Ethan Eismann explained the company’s thinking in an interview with The Verge.

“This is the largest redesign in Slack’s history,” explains Ethan Eismann, vice president of design at Slack, in an interview with The Verge. “We’ve taken a lot of the historical features and reorganized them in a way that makes them much more apparent in the right way and simple to use. That was very much the goal of this process.” Slack’s new redesign all starts with the sidebar. The biggest change is that messages, channels, and apps will all now support grouping into collapsible sections within the Slack sidebar. That means if you’re working on a project that has certain channels and group DM conversations, then you can nest them all under one handy section and drag and drop it to exactly where you want it in the sidebar. Unfortunately, the new sidebar sections feature will only be available on paid Slack plans, not free versions.