Jingzhi T worked on the LifeSG/web-frontend-engine repository, focusing on enhancing type safety within the frontend engine. He refactored the TFrontendEngineValues typing from a union to a mapped type using advanced TypeScript features, which improved the accuracy of input structure reflection and type inference. This change reduced runtime risks and made the codebase easier to maintain, laying a stronger foundation for future enhancements. Jingzhi demonstrated skills in frontend development, type definitions, and TypeScript, applying a disciplined approach to refactoring. The work addressed maintainability and safety concerns, resulting in clearer and more robust input types for the frontend engine.