Worked on the vaadin/docs repository to deliver a comprehensive upgrade guide for migrating from Vaadin 24 to 25, focusing on theming, component structure, and TreeGrid hierarchical data handling. The approach emphasized clarity and maintainability by expanding upgrade steps, merging theming sections, and providing detailed explanations of TreeGrid hierarchy formats and indexing. Utilized CSS, Java, and TypeScript to ensure technical accuracy and consistency throughout the documentation. Collaborated with multiple contributors to improve formatting, code-block presentation, and package alignment, ultimately enhancing onboarding for developers and reducing ambiguity and risk during the upgrade process. No bugs were fixed during this period.