A Greenhouse CI (Continuous Integration) developer manages the automation of coding tasks to streamline the development process. They ensure efficient code integration from multiple sources into a shared repository. They test each change to detect errors quickly, enabling developers to rectify issues promptly. They also facilitate automated testing, saving time in the development cycle. Moreover, they manage the deployment pipeline, ensuring smooth and continuous delivery of software. Their role also includes managing the configuration and maintenance of the CI environment, implementing best practices, and supporting the team in resolving issues related to the CI process.