They are there because they are used to think that way. It's conways law written all over it... There's no actual reason for them to do it. They replaced their

They are there because they are used to think that way. It's conways law written all over it... There's no actual reason for them to do it. They replaced their paperwork with a system that does the same thing. Fraudulent transactions can you find without the need of summarizing it. Yes you can do DDD/CQRS without ES but CQRS is not needed, it's just a technical construct not solving any verifiable problem. DDD on the other hand is more sane and to some extend, verifiable.