I'm considering applying into an (individual) PHD program, after graduating from a top Russian university (computer science) with moderately high grades in 2013 and 3 years of professional experience.

However, I didn't notice whether mentioning recommendation isan necessary case for applying within the official and semi-official sources, I suppose it would be useful. But I'm not entirely sure how it is technically done.

I have a supervisor at the university, whom I have not stayed in contact with since 2013. Is it appropriate to email him with "Hello, I've decided to apply into a PHD program, could you provide a recommendation letter"? Do I get it correctly: if his answer is "yes, sure", then I will include his email in my cover letter (or CV?) and my potential PHD supervisor will send him an email, if interested in my case? Is it true that I will not see the recommendation, at all?

I also have a job, which is (somehow) relevant to my potential field of study. Getting a recommendation from my employer would be possible, but is it worth it? In one hand, our company is small and not widely known. On the other hand, it is pretty innovative and lead by a professor of the same University, at which I got an undergraduate degree. He personally didn't teach me, but I think he can confirm my research skills, as research is what I mostly do as my job. The output were not academic papers, but improving stuff within our developing tasks.

If the target country does matter: I am interested in German-speaking European countries, primarily Germany.