During April 2025, Daniel Pogodars worked on the oarepo/oarepo-runtime repository, focusing on backend development and validation using Python. He addressed a critical bug in ISBN handling by enhancing the robustness of ISBN validation, ensuring canonical ISBNs are properly generated and masked, and introducing a safeguard to raise a ValueError if the canonical ISBN is empty. This work improved data integrity and reduced the risk of invalid catalog data entering downstream systems. Daniel also managed a non-functional version bump to prepare the package for release, maintaining clear traceability and structured versioning throughout the update process. The work was focused and precise.