Spring Security was so massive and difficult that I couldn't muster the courage to study it. Moreover, with version updates, many parts changed, making existing online materials poorly matched and learning quite challenging. However, through this course, I was able to learn and understand the authentication and authorization processes and architecture of the latest Security 6 version from the basics. It was tremendously enjoyable to experience the overall flow and structure of Security. The course content and level were very appropriate and extremely helpful. Thank you for the high-quality lecture. I can say with certainty that this course is the most overwhelmingly superior level of instruction on Spring Security.