Exactly. In Germany there is no "grad school" or "grad students". You get hired directly by a prof to work in their department as a researcher/research assistant ("scientific employee/colleague") and indeed "research some stuff", work on industry collaboration projects, supervise student theses and so on. If you can publish a few papers about that stuff at relevant places, you can write it up and defend your thesis.

There's no "program" to speak of, no bureaucratic application procedure, no handholding.

But the differences start even earlier: in Germany even bachelor and master students are supposed to be rather responsible individual adults, than in Anglo countries. For example it's largely up to students to attend lectures or not, there's little homework, little to do during the semester. You can decide to take or drop courses deep into the semester, then take exams. If you prefer to work during most of the semester and cram everything into the exam period, it's up to you. The opposite is called "verschult" ("schoolized") and has pejorative connotations.