Chapter 3 - The aggregate mixes technical and business aspects
continues from Chapter 2 - The Aggregate does not fit the story telling
Let me introduce villain number 2.
The aggregate mixes technical and business aspects.
For some reason, consciously or not, we try to bring together, in the aggregate, two different models:
- the model to guarantee the invariants
- our mental model of the domain concept
Although this may seem natural, often, these two models do not coincide. Strong consistency constraints do not always reside within the same business concept. It may happen that there are consistency constraints in the intermediate area between two or more business concepts.
Chapter 4 - The larger the Aggregate, the greater the contention