In October 2025, Ievgen Chupryna developed a user language preference update feature for the xm-online/xm-uaa repository, enabling users to personalize their language settings. He implemented this functionality by extending the AccountService with an updateLanguage method and exposing it through a new REST endpoint in AccountResource, using Java and Spring Boot. The solution included a dedicated LanguageChangeRequestVM data transfer object and comprehensive unit tests to validate both service and REST layers. This work improved the system’s localization readiness and accessibility, demonstrating a solid grasp of backend development and REST API design, though it focused on a single feature without bug fixes.