Technical code and business code should be kept separate. That seems like a simple architecture rule. But it is violated in virtually every real project. Even current frameworks like Spring, Hibernate and co. easily contaminate our domain models.

In this talk, we look at ways out of this misery and when and how much pollution might nevertheless be acceptable. This will be helped by

- an understanding of the Domain Logic Patterns: Transaction Script, Table Module, Domain Model,
- the architecture styles Onion, Clean and Hexagonal Architecture and
- tactical design from DDD.