Data at rest is dead data. Immutable data isn't really data at all, or not the data that matters; it's just scaffolding and structure to lend predictability to your real data, which is always in flux and transition.
Your business is an event built on top of events. Shift your frame and so much shit falls neatly into place.
(Because resting state is dead state, all you actually care about about are events and their context. What is happening? What's changing?)