Worked on the OpenTTD/OpenTTD repository to deliver a performance-focused update for the Rail Station Building GUI, implementing UI-level optimizations using C++. The approach involved reducing unnecessary rendering by updating tile highlights only when required, achieved through the introduction of a SetSelectedSize helper. Additionally, the developer refactored lengthy GUI loops to improve code readability and maintainability, aligning with internal quality standards. This work not only enhanced the responsiveness of the GUI but also established a foundation for future performance improvements. The changes were delivered through focused, traceable commits, demonstrating skills in GUI development and performance optimization within a complex codebase.