5 exercises — Learn domain event naming, schema vocabulary, thin vs fat events, and integration vs domain events.
0 / 5 completed
1 / 5
Your team debates whether to use a thin event or a fat event. Which statement is correct?
Thin events (reference events) force consumers to make additional API calls to get data, reducing payload size but adding coupling. Fat events (notification events with payload) reduce coupling but increase payload size and schema surface.
2 / 5
Which event name follows correct domain event naming conventions?
Domain events are named in the past tense using PascalCase: 'OrderShipped', 'UserRegistered', 'PaymentDeclined'. Present/future tense names confuse events with commands; verb-first names ('ShipOrder') are commands.
3 / 5
A correlation ID in an event schema is used to:
A correlation ID (or trace ID) is set at the start of a business process and propagated through all events and service calls. It enables end-to-end tracing — you can find all events from a single user request.
4 / 5
What distinguishes a domain event from an integration event?
A domain event represents something meaningful within a bounded context — it uses the domain's ubiquitous language. Integration events cross context boundaries and must be more stable, versioned, and deliberately designed.
5 / 5
Fill in the blank: "We discovered schema drift — the ___ had changed without updating the consuming services."
Schema drift in event-driven systems occurs when the event schema (field names, types, required fields) changes in the producing service without corresponding updates to consumers — breaking the event contract between services.