A defect resolution developer is responsible for identifying, diagnosing, and rectifying bugs or defects in software systems. They scrutinize software, identify anomalies, and use their programming skills to correct errors, enhance system performance, and ensure the software operates as intended. They collaborate with other software professionals, like testers and system designers, to understand the software's functionality and performance requirements. They also work on updates and patches to fix recurring issues. These developers play a crucial role in maintaining the quality of software products and enhancing user experience by ensuring seamless performance and functionality.