What is Nexus and how does it help scale Scrum?

Nexus is the official Scrum.org framework for scaling Scrum to 3–9 teams working on a single product. It adds minimal overhead over standard Scrum: (1) Nexus Integration Team (NIT) — the new accountability: includes a Product Owner (shared), a Scrum Master, and members from Development Teams. Accountable for ensuring Teams integrate their work into a single valuable Increment each Sprint; (2) Nexus Sprint Goal — an overall Sprint objective that all teams contribute to; (3) Extended events — Nexus wraps Scrum's events: Nexus Sprint Planning (overall integration planning), Daily Nexus Scrum (NIT-level coordination of cross-team dependencies), Nexus Sprint Review (all teams demonstrate integrated Increment), Nexus Sprint Retrospective (multi-team retrospective); (4) One Product Backlog — single PO, single ordered backlog for all teams; (5) Integration Increment — all teams integrate their work into one Increment per Sprint. Nexus is leaner than SAFe and more structured than ad-hoc Scrum of Scrums. It preserves Scrum's empirical process and team autonomy while adding just enough coordination structure.