In March 2026, Hmaior delivered a Fluent-based localization upgrade for the Filter List Dialog in the thunderbird/thunderbird-l10n repository, focusing on software internationalization and localization consistency. The work involved migrating existing localization to the Fluent Translation Language (FTL), adding a new label for the active filter column, and ensuring the user interface met modern i18n standards. Hmaior validated and documented the migration process, which reduced translation overhead and improved maintainability across related UI components. This project demonstrated depth in applying Fluent and localization best practices, while also strengthening the team’s approach to future internationalization efforts within the Thunderbird ecosystem.