The first introductory lecture I heard was a pleasant opportunity for me to broaden my horizons. The core principles I heard after that were like a compass that showed me the direction I should take in the future. I am a PHP developer. Before listening to Younghan's lecture, I was always anxious and uneasy, but after listening to the lecture, I felt much better. I will refer to the roadmap and completely conquer Younghan's lectures in 2023. I will study hard and learn well so that I can apply it to my work. Your voice is also nice, thank you very much.