[JonoW]

Just because you use c# doesn't mean your whole stack needs to be Microsoft. No reason why you could have Windows web-servers running asp.net/c#, but have postgres DB, nginx, memcache etc on linux. Azure seems to be actually encouraging this.

The cost of windows licenses for web-servers is not that much. Avoiding SQL Server is the big win in reducing cost.

[Styck]

All true but there is still quite a bit of inefficiency involved if you need a team that is both proficient in deploying & running Linux infrastructure tools as well as Windows servers.

And given that this discussion is taking place in the comments section of a link to a custom-made monitoring dashboard that quite possibly wouldn't be needed* if SO was a Linux-only shop doesn't exactly devalue my previous statement.

*I have no idea whether this could be replaced with Nagios or Munin