Andy Silv focused on enhancing the reliability of the Filestore POSIX test suite in the ydb-platform/nbs repository by addressing a persistent issue with mknod-related tests. Using C and shell scripting, Andy enabled bind syscall support and expanded the misc.sh test harness with create_file and dirgen_max functions, directly improving test coverage and POSIX compliance. This targeted fix resolved issue-4541, leading to more deterministic and stable test outcomes in continuous integration workflows. Andy’s work in system programming and testing reduced flaky failures, streamlining the development process for downstream features that depend on consistent Filestore behavior.