Worked on expanding test coverage for the executorch/XNNPACK backend, focusing on the absolute value operation in legacy mode. Developed and integrated new unit tests using Python and PyTorch, enhancing the backend’s reliability by validating both standard and legacy lowering paths. This approach reduced regression risk and supported safer, faster backend optimizations. The work involved extending the existing test framework within the pytorch/executorch repository, ensuring comprehensive validation for backend operations. By strengthening the correctness of the XNNPACK integration, the developer contributed to more robust backend development practices, emphasizing thorough testing and maintainability without addressing any bug fixes during this period.