What, exactly, is a product manger?

Marty Cagan describes the job of the product manager as “to discover a product that is valuable, usable and feasible”. Similarly, I’ve always defined product management as the intersection between business, technology and user experience (hint – only a product manager would define themselves in a venn diagram). A good product manager must be experienced in at least one, passionate about all three, and conversant with practitioners in all.