I don't think it's worth paying 30,000 won to listen to.. I recommend that you search for the design patterns listed in the lecture list on the Internet and buy it if you don't understand them. 1. The example code is not an example of practical application, but it ends at the level of "This is called a ~ pattern" while looking at simple example code. -You can learn everything by Googling. 2. The number of patterns taught is also small. If you're going to record a lecture with this level of quality, wouldn't it be right to upload more patterns? 3. The lecture sound is also too low... [Conclusion] I would have been grateful if it was a free lecture, but I don't think it's worth paying 30,000 won for. I think around 10,000 won would be appropriate.