Hexagonal vs Clean Architecture

Hexagonal architecture and clean architecture are closely related — clean architecture is essentially an evolution of hexagonal with more explicit layering. Understanding their similarities and differences helps you choose the right level of structure for your project.

What They Share

Both architectures enforce the same fundamental rule: dependencies point inward. Domain logic at the center has no knowledge of databases, frameworks, or external services. Infrastructure concerns live at the outer boundary and depend on abstractions defined by the core.

Where They Differ

Hexagonal architecture defines two regions: the domain core (inside) and adapters (outside), connected through ports (interfaces). It is conceptually simple but leaves the internal structure of the domain core to the developer.

Clean architecture adds explicit layers within the core: Entities (enterprise business rules), Use Cases (application business rules), Interface Adapters (controllers, presenters, gateways), and Frameworks (web, database, external services). Each layer has a clear responsibility.

The Use Case Layer

The most significant practical difference is clean architecture's explicit use case layer. In hexagonal architecture, application orchestration logic often lives alongside domain logic. Clean architecture separates it — use case objects coordinate entity interactions without containing business rules themselves.

This separation is valuable in complex applications where the same entities participate in many different workflows.

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The Bottom Line

Hexagonal and clean architecture solve the same problem with different levels of prescription. Use hexagonal for simpler projects that need domain isolation. Use clean architecture when explicit layering and use case separation add clarity to a complex codebase.