An Agile Development methodology developer is responsible for designing, implementing, and testing software using an iterative approach. They participate in planning sessions to break down large projects into manageable tasks, known as "sprints". They engage in daily stand-ups to discuss progress and roadblocks. They write clean, efficient code and collaborate with teammates to integrate individual components into a unified system. They also conduct unit testing and facilitate user acceptance testing. The developer actively embraces change, adapting to evolving requirements. They ensure continuous delivery of valuable software, prioritizing customer satisfaction and open communication.