A Concurrent Version System (CVS) developer manages versions of software projects, enabling multiple developers to work simultaneously. They handle changes, control versions, and resolve conflicts in code. They also maintain the history of project development, ensuring easy recovery of any version. They work on bug tracking, release management, and software building. They ensure the consistency and integrity of projects by tracking modifications in a file or set of files. Additionally, they manage branching and merging of code, allowing different versions of projects to be developed in parallel. Thus, a CVS developer plays a crucial role in collaborative software development.