Miguel developed the Avatar Retrieval API for the worldcoin/wld-usernames repository, focusing on efficient and reliable user avatar lookups. He designed the API using Rust and Axum, integrating Redis to cache avatar URLs and minimize backend load, which improved response times and system scalability. The implementation included fallback logic to serve default avatars and robust error handling for missing data, as well as redirection support to maintain link stability when usernames changed. Miguel’s work demonstrated thoughtful backend development and maintainable code structure, addressing both user experience and operational reliability without introducing critical bugs during the release period.