Product Manager
The person who owns what gets built and why, then defends those decisions against everyone who wants something else built instead.
A Product Manager owns the what and the why, not the how. They decide which problem the team solves next, why it matters, and what “done” means for the customer. They do not write the code, they do not run the sprint as a manager, and they do not design the architecture. Their job is to make sure the team is building the right thing before anyone argues about how to build it well.
The role is mostly judgment and communication under conflicting pressure. Sales wants the deal-closing feature. Support wants the bug fixed. The founder wants the bold bet. A good PM holds all of that, says no to most of it out loud, and ships the one thing that moves the business. They are accountable for the outcome, which means they own the roadmap and the prioritisation calls, not just the backlog grooming.
Product Manager versus Product Owner is where most teams get confused. Product Owner is a specific Scrum role: it owns and orders the backlog so the development team has a clear next thing to build. Product Manager is the broader business role: market, strategy, pricing input, stakeholder alignment, and the why behind the roadmap. On a small team one person wears both hats. On a larger one the PM sets direction and the PO turns it into ordered, ready-to-build work.
The common mis-hire is a PM with no authority. If the roadmap is really set by the loudest stakeholder and the PM just writes tickets, you have hired a project coordinator and called it product. We slot product ownership into founding teams as part of a fractional co-founder engagement when the founder is too deep in the build to own it.