Unfortunately I can't name any names, but I can say that Uber isn't the largest company Mattermost, neither in terms of revenue nor number of employees. I don't know for how long not-Uber has been using it, but at least a bit more than a year now.

Neat. Thanks! I haven't kept up on other-users outside of the uber post, good to hear there are more fish in the ocean :)

the fact that companies like HP builds/sells mattermost deployment/support/... yet internally still relies on lync is a joke (and pain to live with)

They use Mattermost internally, they don't sell it to customers (not sure if you were assuming I was talking about HP or a similar company that just deploys Mattermost for customers).

hp, hpe, dxc.. whatever 'division' is one part of .. then it must be deployed in a small amount of centres as most support teams (of any kind) that I've interacted with were all tied to lync only