A developer designs and implements graphics applications using the Java API. They create interactive graphics for applications such as games, virtual reality, scientific visualization, and computer-aided design. Their tasks include creating objects, applying textures, managing lighting effects, and handling user interactions. They also optimize the performance of applications, debug issues, and ensure cross-platform compatibility. Additionally, they might need to integrate applications with other software or systems. Their work involves strong knowledge of Java programming, mathematics, computer graphics principles, and often, familiarity with other graphics libraries.