Feed
In my experience with Onion Architecture, I found that the most challenging aspect was ensuring that communication between layers was purely through interfaces. Early in a project, I inadvertently coupled some implementations too closely, which made refactoring later on quite tedious. Adopting a strict interface-driven approach from the start greatly improved the flexibility of the application in the long run.
The layer-by-layer dependency setup is clear, but I'm curious about how you handle cross-cutting concerns like logging and caching — do those live in the infrastructure layer or get injected through the application contracts? In larger .NET projects I've seen the application layer grow unwieldy when every cross-cutting concern routes through the same abstraction boundary.
Hi Anil, this was a really helpful guide! I liked how you explained each layer step by step, especially the folder structure and how the dependencies should be set up. It made things easy to follow.
One small suggestion — maybe in the future, you could add a section on how to write unit tests for the Domain or Application layer. That would be useful for people trying to test their code properly.
Fabio Sarmento
Artificial Intelligence
Your breakdown of Onion Architecture highlights its strengths in managing dependencies and maintaining clean boundaries. A practical example of this is using the Dependency Injection pattern within the Application layer to easily swap out data sources—like replacing a SQL database with a NoSQL option—without impacting the core business logic. This allows for rapid prototyping and testing while adhering to the principles you've outlined.