I'm leaving a review with only the last section left. I think I enjoyed this lecture especially. The design patterns that I've only heard about as important here and there, The concept of proxy that Younghan mentioned here and there in previous lectures, And Spring AOP using proxy All the contents were interesting. And separately from the lecture content, what I liked about this lecture was that the concepts were explained with test code for each content. In previous lectures, the concepts were usually explained while gradually completing a specific project, But in this lecture, the concepts were explained compactly through independent test codes along with the project, which was very useful for reviewing and organizing. I heard that you finished the Spring and JPA lectures and are now preparing for the Java lecture. I really want to hear Younghan explain the concepts and usage of generics, lambdas, streams, etc. I hope you will continue to give good lectures in the future.