Hexagonal Software Architecture for Web Applications Course Syllabus

Overview: This course provides a hands-on introduction to Hexagonal Architecture (Ports and Adapters) for building maintainable, testable web applications. Over 8 modules, each taking approximately 1 week (6-8 hours), you'll learn to isolate domain logic, implement adapters, and test effectively. The course uses real-world examples and a consistent code-driven approach to demonstrate how to evolve and deploy decoupled systems.

Module 1: Introduction to Hexagonal Architecture

Estimated time: 7 hours

• Evolution of software architecture
• Limitations of traditional layered designs
• Hexagon model overview
• Sketching the hexagon diagram for a To-Do application

Module 2: Defining the Domain & Ports

Estimated time: 7 hours

• Core domain modeling
• Boundary interfaces (ports)
• Use-case definitions
• Writing domain entities and port interfaces for task creation and querying

Module 3: Building Inbound Adapters

Estimated time: 7 hours

• HTTP controllers as inbound adapters
• CLI interfaces as entry points
• WebSocket entry points
• Implementing a REST adapter with a lightweight web framework

Module 4: Developing Outbound Adapters

Estimated time: 7 hours

• Persistence adapters using SQL and NoSQL
• Messaging adapters (Kafka, RabbitMQ)
• External API clients
• Creating a database adapter using an ORM behind a repository port

Module 5: Wiring the Application & Configuration

Estimated time: 7 hours

• Dependency injection fundamentals
• Wiring ports to adapters
• Environment-based configuration
• Bootstrapping the application in a main entry-point

Module 6: Testing Strategies

Estimated time: 7 hours

• Unit testing domain logic with mocked ports
• Integration testing of adapters
• End-to-end validation
• Writing tests with fake adapters and in-memory databases

Module 7: Error Handling & Cross-Cutting Concerns

Estimated time: 7 hours

• Exception translation across adapter boundaries
• Logging via outbound ports
• Metrics and monitoring patterns
• Security adapter implementation

Module 8: Deployment & Evolution

Estimated time: 7 hours

• Containerization of adapters with Docker
• Versioning ports for backward compatibility
• Gradual replacement of adapters
• Demonstrating database adapter swap

Prerequisites

• Familiarity with a web stack (e.g., Node.js, Python, or Java Spring)
• Understanding of dependency injection concepts
• Basic knowledge of databases and REST APIs

What You'll Be Able to Do After

• Design and implement Hexagonal Architecture in real web applications
• Isolate domain logic behind well-defined ports for testability
• Build and swap both inbound and outbound adapters
• Apply robust testing strategies across architectural layers
• Evolve and containerize adapters for deployment and maintenance