Funnily enough, mattermost seems to list Uber as their client on their home page. https://mattermost.com

Maybe they realised it was a superior solution to building their own app.

> mattermost seems to list Uber as their client

Not directly related to mattermost and Uber, but companies tend to list clients even if the product is not widely used or was even dumped.

You are a small team in a big company, you evaluate a product and find that it satisfies some of your basic needs but want to work with it for a while, so you purchase a couple of licenses for you team but stop using it after a year or two.

voilà ! you are a client listed on their web site

> Maybe they realised it was a superior solution to building their own app.

Uber's internal chat tool is built on top of Mattermost.

That's unfortunate - they could have made Mattermost on par with Slack instead.

+1 for mattermost. Works out of box for most applications. But I think people will find it surprising how quickly one starts to run out of space. People can be very chatty.