Scaling Java-Based Real-Time Systems: The Hidden Tradeoffs of Event-Driven Design
InfoQ, Tuesday, June 30th, 2026
Event-driven architecture creates hidden tradeoffs in real-time systems needing immediate responsiveness.
Author Sagar Deepak Joshi describes building a contact center platform handling 80,000 concurrent agents, where adopting Kafka-based event-driven architecture created unexpected production challenges.
The core issue is that event-driven systems are inherently asynchronous, yet real-time communication requires near-synchronous responsiveness on critical paths like call signaling and agent state. The article traces three generations of state management, from Kafka Global State Stores through local caching to a Redis solution with resilience layers.
Failures included consumer lag cascading past 30 minutes due to synchronous REST calls blocking consumer threads. The author concludes that consumer threads should be treated as sacred and never blocked by external dependencies.