In this book, we are building a complete working server, and again we rebuild the whole thing on a different framework. It's about testing out a new approach. If the architecture is honest, the second version costs almost nothing and the business logic never moves. We ran the test, and I let you watch the result rather than describing it.
Every tutorial gets you to "Hello World." This book gets you to production. In 26 years of building and consulting on enterprise systems, I've seen exactly where the gap is, this is the book I wish existed when I started. You'll understand not just how to write the code, but why real systems are built the way they are.