Robert Sajdok developed a theme toggle feature for the gluestack-ui repository, enabling users to switch between light, dark, and system-based color schemes. He implemented system-preference detection and updated UI icons to reflect the current mode, ensuring a seamless user experience. The work involved refactoring theming logic to support system mode and align with the Expo Starter Kit workflow, focusing on cross-platform consistency and onboarding readiness. Using React, JavaScript, and TypeScript, Robert synchronized color-scheme handling across components. The feature addressed accessibility and usability, demonstrating depth in front end development and careful integration with existing Expo-based application structures.