We are lucky, because there are so many great choice for building a media site or a web app. Yes, sometimes you use Ruby on Rails, in some other case, you choose Ember.js, or mix them. Fortunately, Google indexes and tracks the properly architected SPA-s as well, meanwhile FastBoot like solutions will improve this experience further. (FastBoot is Ember.js’ server side rendering tool.) Less and less problem what we have to solve. I feel the future of SPA’s looks quite promising and they will be very important part of our web architecture toolset.