At work I&#x27;ve been implementing some rough CQRS&#x2F;DDD stuff for &quot;the 2.0 system&quot;, and I&#x27;d summarize them as:<p>CQRS: Writes&#x2F;commands and Reads&#x2F;queries are fundamentally asymmetrical. Accept it and take advantage of it by having separate pipelines with different features.<p>DDD: Collaborate with the business-folk to discover <i>their</i> mental-model, and treat it and the code-model as similar co-evolving pieces. Focus on behavior and rules more than pigeonholes for data. Use Repositories to handle how RAM is not infinite, and Services for stuff you truly can&#x27;t fit into meaningful objects.