Application Layer — Orchestrating Use Cases

The application layer coordinates domain objects to fulfill use cases without containing business rules itself.

Responsibilities:

1. Use case orchestration — commands, queries, workflows.

2. Transaction boundaries — begin/commit/rollback units of work.

3. Integration with infrastructure via interfaces.

Example: Application service handling "PlaceOrder" command, delegating to domain entities and repositories.

Architecture impact: Keeping use case logic in the application layer prevents controllers or infrastructure from becoming bloated and untestable.

Reference:

Microsoft: Application Core in Clean Architecture

https://learn.microsoft.com/dotnet/architecture/modern-web-apps-azure/common-web-application-architectures#application-core