Pros and cons

What you gain

The directory is the dependency rule. domain/ has no import path that reaches infra/ without climbing out of the folder, and a review can see that. Every use case is under application/. Every mapper is under infra/ or presentation/mappers. Tests follow the same split: test/unit/domain, test/unit/application, test/integration.

A workflow that touches two features has a home. It stays a use case in application/, calling both ports. You do not have to decide which feature folder owns the workflow.

What it costs

A change to notes touches domain/notes, application/notes, infra/notes, and presentation/notes. Someone new to the tree follows one request across four directories.

The shared files grow. app/use_cases.dart and presentation/mappers/wire_mappers.dart become the hotspots, because every feature adds a factory and a mapping function there. That concentration is the point of the layout, and it is also why the files get long.

Back to the introduction, or continue to when to use it.