During November 2024, Dmytro Tsymbalenko developed a centralized authentication error handling modal for the EveryBuy/every-buy-front repository, focusing on improving user experience in login and registration flows. He refactored existing authentication components in React and Next.js to integrate the new modal, standardizing error messaging for server issues, invalid credentials, and unknown errors. By leveraging TypeScript and SCSS, Dmytro ensured consistent UI feedback and established a scalable foundation for future error handling enhancements. This work addressed user confusion during authentication, improved reliability, and laid the groundwork for reduced support requests, demonstrating thoughtful frontend architecture and a strong focus on UI/UX development.