The lesson study methodology allows Extension educators to reflect on instructional practices and gather formative data that can be used to refine curricula. We trained Extension educators and formed a community of practice (CoP) of agents who used the lesson study method to inform improvements of a 4-H coding curriculum. The CoP planned and set goals, implemented the lesson, shared formative data, and strategized on how to improve subsequent lessons. They found the lesson study method to be an effective tool for engaging the specialist, other agents, and youths in meaningful dialogue so that curriculum goals could be met.