In October 2025, J. Schouten delivered UI Design System Theme Standardization for the nl-design-system/themes repository, focusing on unifying the application's visual identity. Schouten implemented foundational CSS theming and initial house style adjustments, establishing a consistent look and feel across all components. By leveraging CSS and JavaScript within a front-end development context, the work reduced styling debt and improved brand consistency throughout the app. This standardization enables faster UI iterations and simplifies future maintenance as new themes or variants are introduced. The depth of the work lies in creating a scalable theming foundation that streamlines component styling and supports ongoing design evolution.