When to use it

Choose layer-first when the domain is shared and a workflow can touch more than one feature. A Serverpod API that groups several aggregates in one use case wants every port findable under domain/ and every workflow under application/.

Choose it over feature-first when you want a lint or a review to enforce the dependency rule by folder, and when you accept touching several directories for one feature.

Choose it over hybrid when the endpoint layer should follow the same horizontal rule as the domain, including a shared wire-mapper file. Hybrid keeps that inner rule and lets presentation split by feature. Layer-first does not make that exception.

If most of the work is a new endpoint on a stable domain, hybrid will feel lighter. If two features must not grow two copies of Note, layer-first keeps the entity in one domain/notes.

The dependency rule does not change if you pick a different track. Domain is the same note either way.