During August 2025, Mateusz Goryszewski developed a POSIX-compliant fstat() implementation for the nrfconnect/sdk-zephyr repository, enabling reliable file status queries within embedded systems. He designed the solution in C, using seek and tell operations to retrieve file size and mode while preserving the original file offset, ensuring compatibility with existing file system operations. Mateusz also created comprehensive tests for regular files, empty files, and directories, validating correct behavior across scenarios. His work focused on improving test reliability and portability, leveraging his expertise in embedded systems, file system operations, and the POSIX API to address cross-environment consistency in file status reporting.