Different Kinds of Impedance Mismatch in EA

Different Kind of Impedance Mismatch in EA due to which extracting Patterns is hard

Or the extracted Patters are no pure but they are BBOM dealing with conflicting concerns in one class

All Patterns should be done by keeping these conflicting concerns in mind. Differetn Pattern for different concerns

1. Service Layer vs. Domain Layer vs. Data Layer, High Level Logic vs. Low Level Logic

2. CRUD Domain vs. Complex Domains, Thin CRUD Feature vs. Fat Complex Domain Feature

3. Commands vs. Quries Application Services, Request vs. Response


4. OO vs. Relational

5. Different Types Application Logic, involving high level methods calls for

 Persistence Logic or Data Save Logic

Data Fetch Logic or Query DB Logic

Persistence &  Domain Logic 

Interfacing with External Systems

Interfacing with OS Services

CCCs Application Logic