Part III focuses on some of the more advanced topics of developing a build system. Now that you’ve seen the basic concepts (in Part I) and some of the available build tools (in Part II), you can dive deeper into these advanced topics.
The upcoming chapters emphasize the experiences you’d have gained if you worked with build systems for many years. Instead of inventing your own solution to common problems, you can learn from the experience of others. Developers have made many mistakes in the past, and it’s pointless for you to make them again.