The job description varies by product and company; products at different stages of development and growth within the same company demand different things of the

The job description varies by product and company; products at different stages of development and growth within the same company demand different things of their PMs. Fundamentally, the PM's the one who gets the product shipped, whatever that entails. If the product is shipped, the PM makes it a success, including shipping followup features or products. I've heard a few general descriptions, from "does anything except write code" (not true in many circumstances) to "mini-CEO" (implies greater degree of authority than often present). The best one that's stuck is "captain of a pirate ship"; you have to figure out where the ship is going, influencing without authority. On a general level, rough job scope can be in the "design and plan" categories through to execution, driving everything forward, getting approvals and making sure all the edge cases are covered (both in the product and overall, e.g. legal approvals, trademark searches, etc) - plus measuring success, and making sure those metrics are defined and measurable in the first place. Listening to customers, or organizing user studies before launch, and incorporating feedback at every turn. You sit in the middle of the product vision, and while engineers might want to make decisions that seem like good ideas from a technical standpoint, you are the guardian of the context which makes them into great ideas (or not). Similarly, feeding back technical issues and restrictions into the UX design process, and providing those intuitive leaps when you realise if the design goes like this, and the technical architecture like that, the whole thing can be done in a tenth of the time to 99% of the effectiveness.