Pros: You can learn the overall flow of Node js. Cons: First of all, when you do something, you should just do it. Instead of "Why?", I wish you had explained in more detail why you should do it. For example, in the middleware section, there is no simple explanation of what middleware is and why we should install middleware in this class, so you have to look it up on the Internet yourself. And in the same lecture, for example, if you briefly introduce what each role is and why you should use it when scraping the source from the official website, I think it would be easier to practice applying it yourself rather than just simply explaining it. From a beginner's perspective, if you just use it without knowing why you are using it, you will forget it and it will be easier.