I learned a lot of great tips. They are easy to understand and definitely helpful. One thing I regret is that I wanted to get great tips for maintaining clean code like in actual practice, but there were more duplicated codes, duplicated components, and functions with the same functionality than I thought. I thought I would be able to see the code as if it were used in practice and learn how to effectively organize those parts. That's too bad. I think the type definition could be made even more strict. It's a shame. I wanted to see the type script used in practice as strictly as it is used in practice.