Worked on the coolsnowwolf/immortalwrt repository to improve firmware upgrade reliability for WNDAP620 and WNDAP660 devices. Addressed a sysupgrade compatibility issue by updating the uci-defaults script, ensuring the device compatibility version matched the generated image version expected by the upgrade process. This targeted shell-based fix reduced upgrade failures and minimized the risk of device bricking during migrations. Leveraging skills in embedded systems, firmware development, and system administration, the work focused on maintaining release integrity and reducing support overhead. The solution was scoped to minimize risk, preserving customer migrations and enhancing the stability of the upgrade path for affected devices.