OK, I found https://github.com/metasfresh/metasfresh/blob/master/frontend/src/components/Window.js - i.e. it is really so - Window.js looks into the configuration data and composes the final screen from the components automatically indeed.
So, quite a lot of information is provided in the components.
I just wonder - aren’t there cases when the users ask very especific, very complex forms? E.g. I have programmed in my life complex schedulers, planners, complex forms that import the data and processes them and align them with the data in the database and so on. And what about pivot forms, data warehousing, etc.? If application is just data-in-data-out then all the forms can be built in uniform way, but if users require complex processing then there should be custom forms.
E.g. I have seen in other applications graphical builders that builds the payrol calculation schemes (salary, additional compensations and benefits, different taxes and deductions, etc.). But there is no single custom form in frontend.