I enjoyed JavaScript, so I continued to study and work on projects using React and Node Express, but I thought it would be difficult to continue working on the backend with Express alone. As I worked mainly with middleware, I realized that I didn't know much about important concepts (?) of the backend. So I started studying Nest and decided to study Spring properly. Still, since I had some development experience, I think I can take the lectures quickly. I'm studying the concepts that I really need well. I want to become a better backend developer by following the roadmap you recommended. Thanks to Younghan's lecture, I feel like I'm one step closer to my goal. Thank you!