Joe contributed to avatar handling features in the element-hq/element-call and element-hq/element-web repositories, focusing on improving reliability and user experience during authentication failures. He implemented robust avatar retrieval logic using React and TypeScript, introducing Widget API fallbacks and safeguards against stale downloads to ensure fresh and accurate rendering. Joe also added support for MSC4039, enabling avatar downloads when server authentication fails, and wrote end-to-end tests to verify this behavior. His work emphasized code quality through linting improvements and streamlined API detection, demonstrating depth in API integration, front end development, and unit testing while addressing resilience and maintainability challenges.