Delivered a comprehensive Polish localization for the wavelog/wavelog repository, achieving 99.9% coverage across 2,759 application strings to enhance accessibility for Polish-speaking users. Leveraged PO language files and the Weblate translation platform to update UI messages and prompts, ensuring a native user experience. Established a scalable internationalization workflow designed to streamline future localizations, using the Polish rollout as a template for additional languages. Focused on internationalization, localization, and translation best practices, the work improved market reach and usability. All changes were tracked through commit-based traceability, demonstrating a methodical approach to managing language assets and supporting ongoing multilingual development.