During October 2025, Andrey Spirisha enhanced the ydb-platform/nbs repository by developing comprehensive POSIX conformance tests for the Filestore component, specifically targeting the mknod system call. He adapted and extended existing test suites, integrating them into the standard test runner to ensure ongoing verification of POSIX compliance. Andrey created new test files in C and Shell, focusing on file system testing and system call behavior to validate Filestore’s adherence to standards. His work improved the reliability and portability of the Filestore module, providing traceable, automated quality checks that support long-term maintainability and compliance with established POSIX requirements.