Audience engagement is a crucial aspect of virtual events and online platforms, enabling participants to interact in real-time through features such as chat, Q&A sessions, polls, quizzes, and leaderboards. Realtime updates are essential for audience engagement, with technology built on event-driven architecture using the publish and subscribe pattern. Key technical challenges include ensuring message integrity, minimizing latency, maintaining availability, and achieving fault tolerance. To build a dependable realtime solution for audience engagement, it is often more cost-effective to partner with a third-party vendor like Ably, which offers scalable infrastructure and abstraction of the complexities involved in building such systems.