I enjoyed the lecture. The content is good, but the quick feedback was a great help. It was a lecture uploaded last year, but I was able to quickly resolve the parts I was stuck on because you took care of it until now. It is a cost-effective lecture. If you are only familiar with the basics of Spring and Spring Boot and are starting a new project This is a lecture I would recommend before the project. If you only have basic Java concepts such as basic annotations, constructors, Enums, and interfaces, I think you will understand it as you listen to the explanation. I also had a hard time following the flow in the middle part, but since you explained it repeatedly, I felt like I had a better outline by the time I finished the lecture. I learned a lot other than the core Authorization, such as basic concepts of API and Postman utilization, and yml encryption/decryption using Jasypt. Through this lecture, I learned the basic concepts of social login authentication procedures, and I plan to implement a login system using OAuth2 based on the knowledge I learned. I was a bit worried because there was a lot of talk about the microphone and volume, but after listening to it, I realized that it was optional for me... I think people who are sensitive might feel a bit uncomfortable. Thank you for the great lecture.