This document discusses scaling lean principles within organizations. It begins by outlining challenges with scaling lean at the project, program, and portfolio levels, such as optimizing velocity, cross-team coordination, and managing business units. It then presents several principles for scaling lean successfully, including focusing on customer value, valuing learning over delivery, radical transparency, and humility. Tactics for implementing these principles include managing by objectives and key results, evidence-based planning, experimentation, transparency rituals, and modernizing technology stacks. The document emphasizes that scaling lean is as much a cultural and leadership effort as a process effort, requiring a focus on continuous learning and admitting what is not known.