When to use Event-Based Pattern
Multiple subsystems must process the same events
Real-time processing with minimum time lag
Complex event processing, such as pattern matching or aggregation over time windows
High volume and high velocity of data (i.e IoT)
Integration of heterogeneous systems (with different stacks, the event router establishes indirection and interoperability among systems and so, messages remain agnostic)
Cross-account, cross-region data replication : we can scale and deploy services independently from other teams