I felt like I gained thorough knowledge because you explained each principle one by one. It was really good that I could immediately think of what to do first if I were to diagnose while organizing the process in my head. Since I am not a white hacker, I am currently creating an environment to practice using Django and Spring after listening to it twice more, and while developing, the process came to mind and I wanted to use filtering logic. Haha. Anyway, it was a great help and I am very happy! I want to watch the next lectures, Part 2, 3, and 4 soon! [Total 3 times + @ Added after class] After taking the first class, I started my career as a security consultant, and I was able to find SQLi vulnerabilities in almost every project with what I heard in CriHackTive's lecture. And most of all, when I saw consultants with n years of experience not understanding payload and asking me questions, I realized that CriHackTive's lecture had tremendous depth. Through repeated learning, I was able to use WAF bypass and efficient data retrieval in my practice. Thank you again.