Echo JS 0.11.0

He doesn't go into much detail about what makes the stack so scalable. Basically just seems to say that he used Node, and imagine how hard it would be with PHP.

He elaborates more in the comments

yeah i guess so. just thought that for an article called "How I built an app with blah blah blah", he doesn't really say much about how he built it apart from that it's node, which in and of itself doesn't really mean much at all.