The collaboration market is quantified in the tens of billions. Enterprise buyers’ increased desire for information control, compliance and safety suggests a significant chunk of the sector is addressable by open source. Mattermost’s Series B is just another step ahead of fulfilling that fantasy. Congratulations to the team on another great milestone.
Now, Mattermost is announcing a $50M Series B from Y Combinator Continuity and Battery. I’m thrilled to partner with Ali Rowghani from Y Combinator and Neeraj Agarwal from Battery for the next leg of the journey. They share the same vision of open source software software altering the enterprise landscape.

Mattermost’s momentum is due to tremendous developer adoption. Developers enjoy the product because they can customize it. They modify the UI to integrate key development and deployment metrics, embed Mattermost conversation into internal applications, and rich communication service for gifs and emojis.
Customer after customer connects Mattermost for their main systems. Security operations teams create air-gapped networks for incident response, operations teams developing workflows to bring logs from different systems to remediate outages, and IT teams creating powerful workflows to automate inbound support tickets out of their users – all on Mattermost.
Just copy a single file to your own server. And it climbs and scales managing tens of thousands of concurrent orders.
Only a couple months ago, we partnered with Mattermost and led the Series A. We feel that open source applications will be an significant part the future of applications because of their safety, reduced costs of customer acquisition and the flexibility that they provide customers.