In this chapter, we discussed some interesting ideas and an architecture formed by those ideas. Most of the topics focus on a small scope and do their own job, but there are also ideas about putting a whole system together.

The code that implements techniques such as expected error and the approach to managing modules in a project is not hard to apply. But with proper application, it can bring notable convenience to the entire project.

However, as I have already mentioned at the beginning of this chapter, there are too many beautiful things in JavaScript and TypeScript to be covered or even mentioned in a single chapter. Please don't stop here, and keep exploring.

Many patterns and architectures are the result of some fundamental principles in software engineering. Those principles might not always be applicable in every scenario, but they may help when you feel confused. In the next chapter, we are going to talk about SOLID principles in object-oriented design and find out how those principles may help form a useful pattern.