I’m lead dev at Tesults.com and we use this stack. Are you asking about VC backed up companies however? Tesults is bootstrapped and not massive yet so may be there is a reason it’s not used more widely which means I’ll discover why and have to deal with it soon :-) Although I hadn’t heard it’s only used for smaller scale projects, is this anecdotal or is there data?
Interested in the answer too<p>EDIT: I actually use node for my primary product which is a mmo game but it's too soon to consider the organization as a start up.