Katsujukou worked on the oqtopus-cloud repository, focusing on enhancing the TranspileResult data model to improve data fidelity and downstream processing. They restructured the 'stats' and 'virtual_physical_mapping' fields from plain strings to JSON objects, enabling richer analytics and reducing parsing errors for consumers of the API. Using Python, YAML, and Pydantic, Katsujukou updated the backend logic and corresponding tests to ensure the new data structures integrated smoothly and maintained stability across the system. This work strengthened the data contract for downstream services and demonstrated a thoughtful approach to backend development and API design within a short project period.