Consistency: Eventual vs Strong in Clean Architecture.

Strong consistency is handled within Aggregates; eventual consistency is handled via Domain Events and background processors.

In CA, if a change must be immediate, it should happen within one Use Case and one Aggregate. If parts of the system can be updated later (e.g., updating a search index), the Use Case emits an event, and an 'Event Handler' (Adapter) processes it asynchronously.