>I'm not sure why orders/purchases/subscriptions would be seen as mutable. At some point in time, customer X decided to exchange money amount M for a subscripti

>I'm not sure why orders/purchases/subscriptions would be seen as mutable. At some point in time, customer X decided to exchange money amount M for a subscription Y. Think for example about orders where a costumer bought three items and later cancelled one, the order value mutates as it is updated and at most we have a copy of the previous order state before price was updated (for some cases not even that). If you think that’s not a good modeling for financial processes, well so do I, it’s the legacy we’re supposed to manage; moving out from that type of non ideal system to something more solid is what I’m researching.