Event-Driven Patterns, Anti-Patterns, and Architectures

Pattern language is the point of a guide like this. Readers rarely need another abstract reminder that events are useful. They need help recognizing which choices usually produce healthy event systems, which recurring mistakes deserve skepticism, and what a right-sized event platform looks like in practice.

Read the lessons in order. The first distills the strongest recurring good patterns. The second turns the same lens on common anti-patterns. The third gives a reference architecture for a small product team that wants real value without platform sprawl. The fourth expands that into a large-enterprise model where governance, identity, replay control, and observability become first-class platform responsibilities.

If your architecture discussion now has many event terms but still lacks a way to judge whether a design is disciplined, overbuilt, or quietly fragile, Chapter 16 is where the guide turns into a practical review framework.

In this section

• Core Good Patterns
  A practical synthesis of the recurring event-driven patterns that usually create healthy systems, including stable facts, safe publication, bounded consumers, and replayable derived state.
• Common Anti-Patterns
  A practical synthesis of recurring event-driven failure modes, including hidden choreography, callback storms, schema drift, unsafe replay, and platform-wide overengineering.
• Reference Architecture for a Small Product Team
  A practical reference design for a small product team using events in a disciplined, modest way without adopting unnecessary platform complexity.
• Reference Architecture for a Large Enterprise Platform
  A practical reference design for a larger event platform where identity, catalog governance, replay controls, observability, and tenancy concerns become first-class architecture elements.