Netflix is a polyglot shop which uses a number of different programming languages for different parts of their systems. Yes, Node and JS play a large part in that, but that really isn't the whole story.
This is part of a specific re-engineering effort to enable front end engineers write their APIs in single threaded nodejs ..And the platform takes care of scaling.
Because "they already knew js". I know that Hystrix is still core, but IMHO the shift has started.
