I use gulp because so far it is self-explanatory and easy to scale
I use Browserify because it works well with gulp
I use axios because it is isomorphic (universal) and has convenient API
I use Chai because it is best BDD library i know
I use nodemon because it is simple.
I use Turbolinks because it saves my time. In complex applications I still prefer rely on server when it comes to routing.
I use FeathersJS because is a universal way to create API and microservices