In the empowered product team model, the product manager has a clear responsibility, which is to ensure that the solutions are valuable (our customers will buy the product and/or choose to use it), and viable (it will meet the needs of the business). Together with a product designer who is responsible for ensuring the solution is usable, and a tech lead who is responsible for ensuring the solution is feasible, the team is able to collaborate to address this full range of risks (value, viability, usability, and feasibility). Together, they own the problem and are responsible and accountable for the results.
Marty Cagan and Chris Jones in Empowered