If you've done any frontend development in the past few years, you have probably heard of AMD modules, if you haven't already experimented with them. AMD is growing fast, with no shortage of production deployments around the world. This modular movement in frontend development stemmed from a lack of a decent way to organize large-scale projects that have many dependencies. Before modules for the web were a thing, the only tool at our disposal for organizing dependencies was the <script> element. This is still an accepted way to pull in JavaScript code—except when there are hundreds of modules.

Modularity, especially frontend web development modularity, is a large topic—too large for this book (let alone for this chapter) to properly address. So let's strip the topic down to the relevant parts for us, the Lo-Dash programmers. It's good programming practice to divide our code into modules that serve a single purpose. This provides a good separation of concerns and allows our components...