Events need ownership
Every event should have a clear business meaning, accountable owner and lifecycle. Technical messages without stable semantics create hidden coupling and make downstream change difficult to govern.
Reliability is designed explicitly
Delivery guarantees, idempotency, retries, ordering and dead-letter handling must be conscious choices. The architecture should make failure visible and recoverable rather than assuming that every message succeeds.
Observability is part of the contract
Correlation identifiers, structured logs, metrics and tracing allow teams to follow a business transaction across services. In regulated environments this also supports investigation, auditability and operational control.
Consistency needs a business decision
Distributed workflows often replace one database transaction with a sequence of state changes. Teams need explicit rules for compensation, reconciliation and manual intervention, based on the business impact of incomplete processing.