Previously, I was only doing development and maintenance of the nature of bug fixes with Flask, but I bought the lecture while studying Spring for a technology transition, and it was very helpful. What I was most curious about was how Spring is used in practice, and which of the various implementation methods is the most efficient. In this lecture, I explained well how it is used in practice and which method is the most efficient. Since I heard that the future lectures will be explained in the same way, I feel like I should listen even more diligently. Thank you.