The document summarizes key aspects of Lean methodology as presented in an Agile Belarus meetup. It defines Lean as a management strategy to create more value for customers with fewer resources in the shortest time. It outlines five Lean principles: define value, map the value stream, create flow, establish pull, and pursue perfection. It discusses how to specify and share value with stakeholders, eliminate waste by shifting mindset, controlling work in progress and lead time using Little's Law, engage and empower teams through decentralization and trust-building, and continuously improve through reflection and implementing lessons learned.