I've only worked on SI projects for 10 years, so I didn't have any experience with JPA or Spring Boot, so I put it off for a while and started to go back to the basics, and I finally finished it in about a month. Usually, I get sleepy when I listen to lectures, but the lectures were focused on substantial content and practical work, so I was able to listen with concentration. Now, I'm going to take the second part of the utilization class. Thank you~