Clean Architecture & DDD Mastery
Lesson 4/30

Tutorials Clean Architecture & DDD Mastery

Hexagonal Architecture (Ports and Adapters)

8 min read Updated 6/24/2026
On this page

Ports and Adapters

Alistair Cockburn's Hexagonal Architecture teaches us that our application is a 'Hexagon' with many sides, each interacting with the outside world via Ports.

1. Ports (The Interfaces)

A Port is a hole in the Hexagon. It's an interface that defines "I need to send an email" or "I need to save a record". The Hexagon doesn't care who is on the other side.

2. Adapters (The Implementations)

An Adapter plugs into a Port. You can have a SendGridAdapter for production and a MockEmailAdapter for testing. You can have a RestApiAdapter for users and a CliAdapter for developers. The internal logic (the Hexagon) stays exactly the same.

3. Architect Insight

Q: "Is Hexagonal different from Clean Architecture?"

Architect Answer: "They are 90% the same. They both share the same goal: Decoupling. Clean Architecture is slightly more prescriptive about the internal 'layers', while Hexagonal focuses more on the 'Boundary' between the app and the outside world. If you understand one, you understand the other."

Clean Architecture & DDD Mastery
Course syllabus
1. Architectural Patterns The Evolution of Architecture: Monolith to Clean Onion Architecture: Dependency Inversion at the core Clean Architecture: The 'Screaming' architecture Hexagonal Architecture (Ports and Adapters)
2. Domain-Driven Design (DDD) Foundations Ubiquitous Language: Aligning code with business Entities vs Value Objects: Managing identity and state Aggregates & Aggregate Roots: Defining consistency boundaries Bounded Contexts: Handling complexity in large domains
3. Advanced DDD Patterns Domain Services: When logic doesn't fit in an entity Domain Events: Decoupling side effects via events Repositories: Mediating between domain and data Unit of Work: Ensuring atomic transactions
4. Implementing the Clean Layers The Domain Layer: Zero dependencies, pure C# The Application Layer: Orchestrating use cases The Infrastructure Layer: Bridging to the outside world The Presentation Layer: Decoupling the UI from logic
5. Patterns for Data & Logic CQRS (Command Query Responsibility Segregation) MediatR: Implementing the Mediator pattern in .NET Specification Pattern: Encapsulating business rules Policy Pattern: Handling complex authorization rules
6. Enterprise Domain Challenges Handling Persistence Ignorance with EF Core Mapping Layers: AutoMapper vs Manual Mapping Validation Strategies: FluentValidation in the App Layer Error Handling: Result patterns vs Exceptions
7. Testing Clean Architecture Unit Testing the Domain: Fast and pure Testing Use Cases with Mocks Integration Testing the Infrastructure ArchUnit .NET: Enforcing architectural rules via tests
8. Real-World Case Study Refactoring a 'Spaghetti' Monolith to Clean Architecture DDD in Action: Modeling a complex Logistics system
Toolliyo Assistant
Ask about tutorials, ebooks, training, pricing, mentor services, and support. I use public site content only—not admin or internal tools.

care@toolliyo.com

Need callback? Share your details