As the name of the course suggests, it was good to learn about core technologies. I was tired of classes that showed portfolios, but after learning the core principles, I gained confidence in Spring and I think I have a good direction for how to study in the future. I am changing my study direction of only learning how to use it without understanding the code. I am grateful to the instructor who explained various fundamental concepts as easily as possible. This lecture is said to be from beginner to intermediate level, but I see different things every time I listen to the lecture again for review. I think this is the advantage of core technology lectures.