Some quick points on DDD&#x2F;CQRS&#x2F;Event sourcing from my perspective. I&#x27;ve been involved in a project and have a number of concerns:<p>Firstly, the main drivers of this i.e. Greg Young&#x2F;Udi Dahan&#x2F;Particular are trying to sell a product and consultancy. While there is nothing wrong with this, there is a significant cost and the motivation to use this architecture is marketing driven rather than logical gains. Make sure it is appropriate for your organisation. 95% of organisations it probably isn&#x27;t. It wasn&#x27;t for ours but overzealous architecture proponents bought the marketing.<p>The cognitive load is immense compared to a smaller system architecture. Every change results in masses of friction, cost and time. Your agility will be destroyed pretty quickly. Also due to the cross-cutting concerns, there is no escape from it other than to port everything away.<p>The products to support it are generally immature, low quality and opinionated to the point that it&#x27;s impossible to integrate cleanly on anything but a greenfield. Expect friction.<p>There are better gains to be had from changing your architecture to a purely service model (I hate the term, but microservices) and skip the whole concept.<p>However if there&#x27;s one thing I have learned that Command-Query Separation is a good model for isolation. The Event Sourcing bit, not so much.