I listened to this lecture after Toby's Spring 6 lecture, and I listened to it intensively in one day, and as expected, I have no regrets. I only used Spring, and I thought of Spring Boot as a framework that simply solves the difficulties of starting for the first time, so I lightly applied it to my work, and while operating it, I roughly used the methods used in Spring, but I realized that I had difficulty customizing it because I did not know these in-depth settings. There are many areas that I need to study more, but I feel like I can see the path because it seems to be a guideline for where to start studying. Thank you for the great lecture. I will happily wait for intermediate or higher level lectures later.