React Chat is a dynamic mobile messaging solution designed to facilitate seamless real-time communication through a polished React Native and Expo frontend , integrating high-performance components like Shopify's FlashList for rendering extensive message histories and Expo Router for smooth navigation. The application ensures a secure and engaging user experience by employing Async Storage for persistent session management, Expo Image Picker for multipart custom avatar uploads, and optimized polling mechanisms via setInterval to update chat feeds, "unseen" message counts, and user online statuses instantly. On the server side, the system is powered by a Java J2EE backend

utilizing Hibernate ORM for efficient database interactions, where standard Servlets handle complex logic such as multipart file processing, regex-based validation for Sri Lankan mobile numbers, and advanced criteria-based searching to filter users. Data exchange is streamlined via JSON and GSON, connecting the mobile interface to a MySQL database to persist user profiles, chat logs, and activity statuses, resulting in a fully functional, full-stack chat environment.