Clean Architecture, formulated by Robert C. Martin, organises code into concentric layers whose dependencies point only inward toward the domain. Business rules sit at the centre, independent of frameworks, UI, and databases at the outer edges. The Dependency Rule keeps the core testable and insulated from external change.

Clean Architecture

Details
Full Name

Clean Architecture according to Robert C. Martin

Core Concepts:

The Dependency Rule

Dependencies only point inward

Concentric circles

Entities → Use Cases → Interface Adapters → Frameworks & Drivers

Independent of frameworks

Architecture doesn’t depend on libraries

Testable

Business rules testable without UI, database, or external elements

Independent of UI

UI can change without changing business rules

Independent of database

Business rules not bound to database

Independent of external agencies

Business rules don’t know about outside world

Screaming Architecture

Architecture reveals the intent of the system

SOLID principles

Foundation of the architecture

Key Proponent

Robert C. Martin ("Uncle Bob")

When to Use:

  • Enterprise applications with complex business logic

  • Systems requiring long-term maintainability

  • When team size and turnover are high

  • Projects where business rules must be protected from technology changes

Criticism:

  • Jimmy Bogard, "Vertical Slice Architecture" (2018) — calls the "traditional layered/onion/clean architecture" monolithic in its approach and appropriate for only a minority of requests, criticizing mock-heavy tests and abstractions "around concepts that really shouldn’t be abstracted"; his alternative is Vertical Slice Architecture

  • Derek Comartin, "'Clean Architecture' and indirection. No thanks." (CodeOpinion) — dismisses canonical Clean Architecture examples as "useless indirection": the layering adds cost without paying for itself in typical systems

  • The critiques converge: the dependency rule imposes a fixed indirection tax on every feature, while most changes cut across all layers anyway — the coupling Vertical Slice Architecture organizes around instead