Worked on the yusei53/refty repository to enhance form validation and data consistency in a TypeScript and React frontend environment. Delivered three features over two months, including a 40-character maximum for reflection form titles and a Zod schema update to prevent whitespace-only titles, ensuring cleaner analytics and improved user experience. Strengthened username validation by enforcing length and alphanumeric constraints, aligning schema and UI logic for reliable submissions. Focused on a validation-first approach, reducing edge-case errors and maintaining consistent data constraints across forms. Leveraged React Hooks and Zod to synchronize frontend validation with business requirements, prioritizing maintainability and robust input handling.