Chat apps have become an integral part of communication, offering a seamless way to connect with others through their complex architecture, which includes both front-end and back-end components. A well-designed chat app architecture is essential for managing real-time message delivery, user authentication, and data security, all while handling a large volume of messages. The chat server engine plays a crucial role, encompassing components such as databases, server-side code, and networks to ensure efficient message processing and delivery. On the client side, the application interface must be user-friendly and responsive to enhance the user experience. PubNub provides a real-time communication platform that simplifies chat app development by offering APIs and tools to build secure, scalable applications with real-time message delivery, robust security features, and support for various use cases. Developers can quickly create a minimum viable product (MVP) for chat applications by integrating PubNub's solutions, which facilitate the seamless transfer of messages and provide resources for building robust chat apps.