Hi @it33
Just using tech that's been built by Google and Facebook doesn't make a solution scalable. Mattermost uses Go. Perfect! One of the reasons, I would like to use Mattermost. But rest of the techstack doesn't seem to be built for scale (we are talking a million users as a minimum). Mattermost uses MySQL or Postgres as datastore. There is no usage of cache. In fact, usage of Redis was removed and the reason given (by you) for it's removal http://forum.mattermost.org/t/is-redis-still-used/97/5 didnot make sense to me. Other than Go, all of the above would constraint me in order to scale operations and make it quite expensive to keep adding mysql servers.
I would also like to mention that I am not interested in using an 'enterprise' version as a solution to scale, which would defeat the purpose of using an open source solution. For enterprise I would simply use Slack or hipchat.
As it stands, Mattermost fundamentally is constrainted for scaling. I have another question open which I hope someone from Mattermost will answer http://forum.mattermost.org/t/scaling-mattermost-for-saas/861