> That seems very dependent on which company you work for. Many would not grant you that kind of flexibility.

It really boils down to what scenario you have in mind. Developers do interact with product managers and discussions do involve information flowing both ways. Even if a PM ultimately decides what the product should do, you as a developer have a say in the process and outcome.

Also, there are always technological constraints, and some times even practical constraints are critical. A PM might want to push this or that feature but if it's impossible to deliver on a specific deadline they have no alternative to compromise, and the compromise is determined by what developers call out.