What's with that Node.js part? Even if it is part of the backend it has nothing to do with the app, so i 'll go ahead and guess either the writer is clueless, or they spit out random trendy jargon in their articles.
Is it possible also that node.js is providing faster response times on the same number of servers?
http://mashable.com/2011/03/10/node-js/
http://venturebeat.com/2012/01/30/dahl-out-mike-drop/
http://nodeknockout.com/judges
Here's an interview she did last year with a Node dev in which she referenced LinkedIn's work with Node for their mobile site.