During July 2025, Fadhil Riyanto focused on maintaining and improving the zephyrproject-rtos/hal_rpi_pico repository, specifically addressing a bug in the C codebase. He identified and corrected a typographical error in the stdio.c file, changing a variable name from 'serialzed' to 'serialized' to enhance code readability and reduce potential confusion during debugging. This targeted bug fix was carefully implemented to maintain backward compatibility and avoid introducing regressions, with updated in-code comments to support future maintenance. Fadhil’s work demonstrated attention to detail in bug fixing and code refactoring, contributing to the overall reliability and maintainability of the project.