A Crestron Toolbox developer designs, programs, and manages systems that integrate audio-visual equipment and control systems using Crestron's proprietary software, Toolbox. They utilize this software to troubleshoot and debug system issues, design user interfaces, and implement custom automation sequences. The developer also collaborates with stakeholders to understand their needs, ensuring the system functionality aligns with their requirements. They conduct system tests, provide technical support, and maintain system documentation. Their role requires a strong understanding of AV technology and networking, along with programming skills, particularly in Crestron's Simpl+ and Simpl# languages.