Directory structure for middleware generators, objects?

Question

Node.js

There are many factories, middleware generators, etc., I want to clean up and structure.
These factories and generators are specific to the application as a whole, not to a specific module.

now the structure is:

- libs
- - errors 
- - helpers
- - utils (тут генераторы middlewares)
- - factories (тут фабрики)
- - builders (тут классы/функции которые относятся к паттерну строитель)
- modules
- middlewares (общие, например обработчик ошибок)

How to correctly name directories with factories, generators, middlewares, etc.? , now it's all in utils, but it's a mess, in my opinion there should be something else in utils, useful functions are common, etc., and not generating functions / classes

Why do I call the directory with errors, helpers, etc. libs ? All my life I thought there some libraries put the

project ready , long abandoned, I study and disassemble for the sake of practice and better understanding of how everything works.