Ive observed a modern trend of little to no QA. Managers and CTOs insist developers can test their own systems. Maybe this makes more sense in the early phases of product development where I find myself lately? Seems to capture a lot of dev's time.
The Product Manager's job is to communicate the customers needs to the developers/designers and the developers/designers constraints back to the customers.
It's up to the developers and designers to understand those constraints and make sure they are communicated back.