The Center for Global Education at Asia Society is supporting a 21st century competencies working group as part of its Global Cities Education Network. City teams in Colorado, China and Japan have been applying improvement science principles to build systems and develop innovative practices that help students develop the skills they need to succeed. This Global Learning blog in Education Week summarizes key lessons learned about system change through these efforts about the role of classroom teachers, system-level supports, and the value of starting small before scaling new practices.