A CruiseControl.NET developer manages the process of continuous integration in software development. They use the CruiseControl.NET framework to automate the build, run unit tests, analyze code, and perform other tasks to ensure the software's quality and reliability. Their role involves understanding the project's build process, setting up the necessary configurations, monitoring the system for any build failures, and troubleshooting issues. They also maintain the server environment for the CruiseControl.NET system. Their work contributes to a streamlined, automated development process, reducing manual errors, increasing efficiency, and ensuring the delivery of robust, high-quality software.