> such as global state, in process locks, interpreter protected consistency guarantees, If you need to share state or you need consistency/locking/transactions

> such as global state, in process locks, interpreter protected consistency guarantees, If you need to share state or you need consistency/locking/transactions across bounded contexts on one service it's trivial to implement. But this can be incredibly difficult to do correctly across multiple servers. No one has implemented a multi-phase commit over multiple services and said "dang that was easy" afterwards.