During December 2025, Po Nuva improved reliability and API quality in SerenityOS/serenity and openSUSE/open-build-service. In SerenityOS, they enhanced POSIX compliance by implementing EINTR retries for read and write syscalls, enforced in-order buffer handling for VirtIO Console devices, and used atomic operations to resolve race conditions in device minor number allocation. They also improved error handling for XZ compression in tar. For openSUSE/open-build-service, Po Nuva developed a secure RESTful PUT endpoint for comment updates, restricting changes to original authors and updating documentation. Their work demonstrated expertise in C++, Ruby, concurrent programming, and robust API development, addressing runtime stability and developer experience.