A DDTS developer works with Cisco's Distributed Defect Tracking System (DDTS), a tool for tracking software bugs and defects. They are responsible for identifying, logging, and tracking issues within the software development process. This involves creating detailed reports of identified defects, assigning them to the appropriate team or individual for resolution, and ensuring the effective implementation of fixes. Additionally, they may use DDTS for project management tasks, like task allocation and progress tracking. Their goal is to enhance software quality, reduce development time, and ensure efficient workflow in the software development lifecycle.