Nico Virkki contributed to the City-of-Helsinki/yjdh and kukkuu repositories by delivering targeted platform upgrades and codebase maintenance. He upgraded kukkuu to Django 5.2, Python 3.12, and PostgreSQL 17, improving deployment flexibility and security by introducing environment-based database password support and refining timezone handling with psycopg-c. In yjdh, he removed deprecated TET Job Search functionality and implemented robust error handling for empty Ahjo decision details, reducing runtime errors. Nico’s work emphasized backend development, CI/CD configuration, and repository cleanup, using Python, Django, and TypeScript to enhance maintainability, documentation, and future readiness across both projects.