Pattern
Consistency
Scale
Complexity
Suitable For




Pessimistic Locking
Strong
Low
Low
Monoliths, legacy systems


Saga Pattern
Eventual
High
High
Microservices


CQRS
Eventual
High
High
Read-heavy systems, DDD


Mediator
Depends
Med
Medium
Coordinated command handling


Event Sourcing
Eventual
High
High
Auditable systems


Two-Phase...