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