An old programming adage says that while functionality is an asset, code is a liability.[8]
Throughout this book, as you learn to harness Node.js, keep in mind that the best line of code is the one you never had to write. If you can get something for free, take it!
However, the nature of a technical book is to teach you how to do something, even if somebody has already done it for you. By understanding how things work, you’ll be better able to build on top of them.
So we’ll be progressing in stages. In the beginning, you’ll be working at the lowest levels of Node.js—getting to know the environment, the language, and the fundamental APIs. As you master those, you’ll learn how to use other peoples’ modules, libraries, and services to replace some of that code and go to the next level.
By the end, you’ll see where it’s possible to make great gains using existing libraries, and where it makes sense to implement the functionality yourself. At the end of the day, this wisdom is the power that will distinguish you from a novice developer.