This is a really, really good lecture. I started listening to it because I was not good at writing test codes, but it helped me resolve many of the questions I had while writing tests and working on projects, such as whether this is the right way to do it or why I had to write it this way. I came to understand very naturally how important design is. Maybe it's because readability is really important for test codes, but the lectures are also incredibly readable. Even a student with shortcomings like me can understand it well. I highly recommend listening to it.