The only thing the word “refactoring” tells me is that you’re rearranging code without changing functionality. It doesn’t tell me why you’re doing it. You could be doing it for all sorts of reasons: to extract part of the code into a separate library, to route around dead code so it can be excised later, to enable a performance optimisation, or to allow a new feature.

What’s going on in this article is refactoring towards a very specific goal. That goal is reaching an architectural style that could also have been achieved earlier in the development process, and it’s that style that is, AIUI, the point of the article.

There is a short mention of “refactoring” and how it is a bad name, I’m not sure why, just read the article in 3mins. TL;DR: start with the complex things, deduplicate code and use proper data structures once you have working code with multiple use cases.