Another challenge that comes with CRUD-based models is to handle competing transactions. Business use cases that include the same domain entities and operate simultaneously need to ensure that the resulting state of the entities is consistent.

Editing a user's name and at the same time updating its account credit limit should not result in lost updates. The implementation has to ensure that the overall result of both transactions is still consistent.

Competing transactions that rely on optimistic locking usually result in failing transactions. This is definitely not ideal from a user's perspective, but at least maintains consistency, rather than suppressing that a transaction has been lost in space.

Following this approach, however, potentially leads to unnecessary locking. From a business theory perspective it should be possible to simultaneously edit the user's name and account credit limit.