A Certified Scrum Master Developer leads the Scrum team, ensuring they understand and follow Agile principles and Scrum methodology. They facilitate communication, cooperation, and productivity among team members. They also act as a buffer between the team and any distracting influences. Their duties include managing Scrum processes, coordinating and guiding the team, and helping the team reach consensus. They assist with product planning, help remove any obstacles hindering progress, and ensure team members adhere to Scrum theory, practices, and rules. They also liaise with the product owner to manage backlogs and maximize value.