Web-based chat applications have become increasingly sophisticated, incorporating features such as message threads, reactions, quoting, and read receipts to enhance user interaction and engagement. PubNub's Chat SDK offers a comprehensive platform for building chat apps, ensuring reliability through automatic reconnection, message ordering, and message persistence, supported by a global edge network to manage high loads and reduce latency. Developers face a decision between building an in-house chat solution or using a vendor-provided service, with Infrastructure as a Service (IaaS) offering a scalable, cost-effective alternative. Security is vital, with advanced authentication systems and encryption protocols like Transport Layer Security (TLS) or WebSocket Secure (WSS) protecting data transmission. PubNub further enhances security with its Access Manager (PAM), which uses role-based permissions and JSON Web Tokens (JWT) for fine-grained access control. The platform's presence feature and real-time messaging infrastructure facilitate multi-device synchronization, ensuring seamless user experiences across devices. As chat applications continue to evolve, they offer new opportunities for customization and integration with advanced technologies like generative AI and virtual reality, creating potential for business growth and innovation in various industries.