What role is primarily responsible for managing the overall ART backlog?

The role primarily responsible for managing the overall Agile Release Train (ART) backlog is the Product Manager. This position is focused on aligning the vision of the product with the needs of the stakeholders and customers, prioritizing features, and ensuring that the backlog reflects strategic goals.

The Product Manager collaborates with different stakeholders to gather requirements, define the product roadmap, and shape the overall direction of the product. They take a more holistic view of the ART backlog, which includes not just individual features but also the prioritization of Epics and initiatives that guide the train's progress towards achieving business objectives.

In contrast, while the Product Owner plays a crucial role in managing the team-level backlog and ensuring that the team is working on the right tasks, the overall ART backlog management is a broader responsibility that falls to the Product Manager. The Release Train Engineer facilitates the processes and activities of the ART without direct responsibility for the content of the backlog. Finally, the Scrum Master supports the Scrum team and helps optimize the team's efficiency, but they do not manage the backlog.