In June 2025, Johannes extended the music-assistant/server repository to support Opus-encoded audiobooks, enabling users to add and play Opus-format content in their libraries. He approached this by updating the configuration management logic to recognize and handle the 'opus' extension, ensuring seamless integration with existing audiobook discovery and playback features. Working primarily in Python, Johannes focused on precise format handling and repository collaboration, carefully testing the new support to maintain stability. This targeted feature broadened the platform’s compatibility, reduced onboarding friction for users with Opus content, and demonstrated a thoughtful, well-scoped engineering contribution within a short timeframe.