We built Mattermost for ourselves — we were originally a video game company, and we were frustrated with the SaaS messaging platform that we were using, which was failing. It was bought by a larger company and was somewhat neglected. It would crash, it would lose data, and we couldn’t use it. We couldn’t export our data and felt trapped. So we decided to solve our own problem and built an open source messaging platform for ourselves that we could trust. We could trust it because we had the source code and we ran it ourselves.
When we released it, we didn’t say “here’s a platform that can do a million different things.” It was just focused on our own use case–a messaging platform we could fully control and trust– but we welcomed feedback from the community, and it grew from there.