A ChucK developer designs, codes, and modifies music and sound applications using the ChucK programming language. They deal with sound synthesis, digital signal processing, and real-time interaction. They use ChucK's unique timing and concurrency models to create precise, complex, and creative audio applications. They also debug and troubleshoot code, optimize performance, and collaborate with other professionals like sound engineers and musicians. Furthermore, they may also write technical documents and teach others how to use ChucK. Their work is often used in concerts, installations, music albums, and research projects.