I really like that stack primarily because it couples c# with an open stack. Could you share a bit more about the web server setup and how you came to choose this stack?
Came to choose: It was the only language that doesn't suck that the entire initial team had some to much experience with. About the open stack, seemed obvious to me - why knowingly lock yourself in? BizSpark is nice, and we're members, but not every startup takes off as fast as Slack and for a struggling company, licenses might be prohibitive.
Server setup: We have 6 docker containers: Postgres, backend, nginx, assets, data and ssh. Backend is a ubuntu+mono+backend_code. Data is the docker data container pattern. Assets is the frontend code (we're an SLA). Ssh is an sshd for looking at the data and logs in the data container.
Nginx and backend talk via fastcgi, one of ServiceStack's apphosts.
Currently it's all on one server, but the code is prepared for scaling and load balancing.