During May 2026, this developer enhanced the security of the decidim/decidim platform by implementing HTML content sanitization for static pages, directly addressing cross-site scripting vulnerabilities. Using Ruby and Ruby on Rails, they applied a test-driven development approach to ensure that unsafe HTML tags and attributes were effectively removed from user-generated content. Their work included expanding the test suite to validate the sanitization process, thereby reducing the risk of XSS attacks for both content editors and end-users. This contribution improved the platform’s reliability and aligned with security best practices, demonstrating a strong focus on backend development and application safety.