Recall that in product there are always four risks:
* Value risk (will people buy it, or choose to use it?)
* Usability risk (can users figure out how to use it?)
* Feasibility risk (can we build it with the time, skills, and technology we have?)
* Business Viability risk (will this solution work for the various dimensions of our business?)In an empowered product team, the product manager is explicitly responsible for ensuring value and viability; the designer is responsible for ensuring usability; and the tech lead is responsible for ensuring feasibility. The team does this by truly collaborating in an intense, give and take, in order to discover a solution that work for all of us.
Marty Cagan, “Product vs. Feature Teams“
I would add a dimension that differentiates great products from products: lovability.
Stupid Matters 