A LightTools developer works on creating and improving the LightTools software, a optical engineering and design software tool. They utilize their skills in coding, programming, and software development to enhance the software's functionalities, fix bugs, and implement new features. They work closely with optical engineers, understanding their needs to develop user-friendly interfaces and efficient algorithms for optical simulations. They also test the software to ensure optimal performance and troubleshoot any issues. Furthermore, they may provide technical support to users, helping them understand and use the software effectively. Their ultimate goal is to facilitate and optimize optical design processes.