This is a lecture that is like a stepping stone for development skills. Veterans create different results with deeper knowledge and a broader perspective even when doing the same work. I think this is the scary thing about years of experience. This lecture imparts knowledge and techniques that can be accumulated through many years of experience. The instructor kindly introduces valuable information and techniques accumulated through his persistent obsession with development and various experiences to beginners like me. When I first saw it, I was surprised the whole time. I was now able to explain the concepts that felt vague in words, and I immediately studied object-oriented programming and applied it as instructed, and refactored it, and the structure of the project became cleaner. When I first saw the lecture, I was still inexperienced, so I was not able to apply the contents you mentioned in various ways. After that, I thought of this lecture while working on a new project. When I watched the lecture again and applied the contents you mentioned, I felt that the code was incomparably improved compared to before, and my project mentor and team members all praised it for being easy to read and well-written. I think this lecture is a lecture that broadens your perspective. It goes beyond simply correcting mistakes and learning the know-how and knowledge of experts, and I think it is a grateful lecture that shows various choices that beginners cannot see when making a choice.