From the introduction to DB 2, I've come this far. This is a roadmap that I highly recommend for the following reasons. 1. Depth of learning In fact, when studying a technology, if it's too shallow, you won't build up your skills, and if it's too deep, it won't be practical. However, I feel like it's organized with the appropriate depth of learning that you've acquired over a long period of time in the field. 2. Breadth of learning Since it mainly touches on technologies that are frequently used in practice, I was able to focus on learning without the question of "So what should I use and how?" At the same time, since it appropriately checks and moves on to basic and non-mainstream technologies, the overall picture is naturally drawn. 3. Examples Since all concepts are explained through examples, it's easy to understand, and the example sources are a great help when reviewing and experimenting on your own later. I can feel how much thought went into creating the examples. 4. Other In addition, I was able to learn IDE tips, unit testing, etc. through live coding, and it was really great that they covered basic parts for beginners, such as logging and exception handling. They also answered quickly and well with supporters, and they were the best!!