I looked for a lecture in a hurry for a personal project, and it was explained really well step by step, so I understood it well! I watched a spring lecture before studying nest.js, but there was no lecture that explained the core slowly and at a beginner's level like this. Thanks to this lecture, I can finally understand similar spring. It was good that it explained the structure of how the server works with pictures in an easy-to-understand way, and explained everything I was curious about. Before watching this lecture, I had questions like, "What is dto? Why do I use it? Dependency injection? What is @ and when should I use it? What are the roles of controller and service and why are they separated?" In some lectures, even if they are beginner lectures, there was no explanation, so I couldn't understand and had to look it up on my own, but I felt relieved because everything was explained one by one. I really like this lecture. It's free when you explain it so well. Does that make sense? Awesome... Thank you so much. Thanks to you, I understood it! I recommend this lecture.