> runs some kind of "agency" or "factory" that runs product engines for startups of software based companies
In most cases the product is the company, so outsourcing that learning, that eventually becomes tribal learning within the company culture, is incredibly dumb. Also to build a great product you have to understand you customers needs and solve problems for them, and you can't embed that understanding to imagine a future for them if you outsource it.
On the other hand there are thought leaders and coaches who will help you, and you can hire fractional executives to get you on your feet. See https://www.svpg.com/articles/
> run product engines
There's an entire profession for this, it's called product management.