I'm actually not doing any server side processing. This means we only ever need to serve static files which means exceptionally easy to scale and incredibly lightweight and fast. Although I'm using node to server these static files for development, if this were to be placed in a production environment I would use something more suitable for serving static files such as nginx (or even a CDN) which will yield much better results. And of course use things such as gzip, js minify, browserify, etc for maximum effect.