Baro Luc enhanced immutable state management in the ariakit/ariakit repository by introducing ReadonlyArray types to both core and React-core store definitions. This approach, implemented using TypeScript and leveraging frontend development and state management expertise, enforced immutability for store data and prevented unintended mutations. By defaulting array values to readonly, Baro improved the reliability and predictability of state flows, ensuring safer and more robust API surfaces for both core and React bindings. The work focused on strengthening data integrity and laying a foundation for future enhancements, reflecting a thoughtful and methodical approach to improving state management architecture.