During April 2026, Vova Kuzaxak focused on improving concurrency safety in the moby/buildkit repository by addressing a data race in the readerAtCloser component. He implemented mutex-based serialization for ReadAt and Close operations, ensuring compliance with the io.ReaderAt contract under concurrent access. This solution, developed in Go and leveraging AWS SDK v2, prevented race-induced crashes during parallel S3 uploads and improved the reliability of large-cache exports. Vova’s patch offered a stable, production-ready fix with minimal risk, while outlining future opportunities for restoring parallelism through stateless or per-offset readers, demonstrating depth in concurrent programming and cloud integration.