The Product Owner (PO) is the person who represents user needs to a development team: they decide what gets built first and make sure what ships actually meets the need. The role comes from Scrum, where it is one of three roles alongside the Scrum Master and the developers.
Day to day, they write and split user stories, order the backlog, define acceptance criteria and sign off on deliveries at the end of each sprint. They bridge users, business teams and the tech team.
The role is most common in large companies and organizations running agile at scale, where the PO often reports to a Product Manager who owns the product vision and strategy.
Why it matters when hiring
The PO is often confused with the Product Manager. The PO drives execution (backlog, sprint, acceptance testing), while the PM owns the vision, the market and business trade-offs. A startup usually hires a PM who also does the PO work. In interviews, ask how they said no to a business request and on what basis: a real PO prioritizes with arguments, a token PO just forwards tickets.