A Choona.js developer designs and implements web applications using the Choona.js framework. This involves creating user-friendly interfaces, developing server-side logic, ensuring high performance and responsiveness of applications, integrating front-end elements with server-side logic, and maintaining database schemas that represent and support business processes. They also work on fixing bugs, improving application functionality, and keeping up-to-date with the latest industry trends. They often collaborate with other team members, like UI/UX designers and software testers, to create optimized and high-quality web applications. They may also be involved in writing reusable, efficient and scalable code.