A Game Closure SDK Developer works on the development, testing, and debugging of mobile games using the Game Closure SDK. They utilize JavaScript and to create interactive, cross-platform games that can run on different devices. They are responsible for optimizing game performance, ensuring seamless gameplay, and incorporating different features like multi-player options, in-app purchases, and social media integrations. They also need to fix bugs and issues that could affect the gaming experience. Moreover, they often collaborate with designers and other developers to produce high-quality games that meet user expectations and business objectives.