An ALV Reports Developer constructs and manages reports using ABAP List Viewer (ALV) in the SAP system. They are responsible for creating interactive, detailed and complex reports containing data from various modules of the SAP system. Their duties include designing, coding, debugging, and testing these reports. They also customize ALV reports based on user requirements, ensuring optimal performance and user-friendly interfaces. They collaborate with other SAP team members to integrate these reports into the overall system. Furthermore, they troubleshoot any issues related to ALV reports and provide technical support to end-users.