Webpack has quickly become one of the most popular choices among web developer build tools. It can quickly build, minify, split & do a whole wonder of other things to your code.
Sample Webpack Config: https://gist.github.com/learncodeacademy/25092d8f1daf5e4a6fd3
Node.js Introduction: https://www.youtube.com/watch?v=pU9Q6oiQNd0
Another great build tool is Browserify, which at the beginning of the process works a LOT like Webpack, but in the end, Webpack is a lot more featureful.