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⚡ Event-Drivenarchitecture-pattern

Event-Driven Architecture

eventspub/subasyncstreamingeda
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Event-Driven Architecture

Summary

Systems communicate through events, enabling loose coupling, async workflows, and reactive behavior.

What it is

Producers emit events describing facts; consumers react asynchronously. Brokers or streaming platforms handle delivery and retention.

Patterns

  • Pub/sub via topics
  • Event sourcing + CQRS
  • Choreography vs. orchestration
  • CDC for legacy integration

Distinctions (pub/sub vs. event sourcing vs. CQRS + events)

  • Pub/Sub: fire-and-forget notifications or data distribution; consumers act independently; minimal state in the broker
  • Event Sourcing: events are the source of truth for state; rebuild state by replaying the event log
  • CQRS + Events: separate write and read models; events propagate changes to build optimized read projections

Trade-offs

  • Complexity in reasoning about flow
  • Event contract governance is critical
  • Eventual consistency impacts UX and design

When to use

  • High throughput, decoupled workloads
  • Real-time analytics and streaming ETL
  • Integrating heterogeneous systems asynchronously

Related Patterns

⚡Event-Driven

CQRS

# CQRS ## Summary Separate write and read models to optimize for different workloads; often paired with events. ## Wh...

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⚡Event-Driven

Event Sourcing

# Event Sourcing ## Summary Persist changes as an immutable sequence of events; rebuild state by replaying events and ...

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⚡Event-Driven

event-message

# Event Message ## Summary An Event Message is used to notify other applications about a change that has occurred in th...

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