JavaScript is the language of the modern web. It has enabled many of the revolutionary experiences created over the past 5 years, from Google Maps to Spotify. However, historically, it has needed to be paired with something else like Python to build out full applications.The emergence of server-side JavaScript means developers can now create rich, lightning-fast applications in pure JavaScript from end-to-end. Focusing primarily on a single language to learn CS concepts, front-end development, and back-end development is a crucial part of what makes the extraordinary rate of learning during the program possible.