Domain-Driven Design (DDD) & Clean Architecture is an advanced software engineering course that emphasizes building maintainable, scalable, and domain-aligned applications. The course begins with an overview of traditional layered architecture and its limitations in complex systems. Learners are introduced to DDD fundamentals, including the concept of ubiquitous language, bounded contexts, aggregates, entities, value objects, and domain events. They explore how to model domains collaboratively with business stakeholders using techniques like event storming. The course then introduces Clean Architecture principles, pioneered by Robert C. Martin (Uncle Bob), which separate application layers—Entities, Use Cases, Interface Adapters, and Frameworks—to ensure flexibility and testability. Learners apply dependency inversion and SOLID principles to decouple business logic from infrastructure. Real-world projects guide learners in implementing DDD and Clean Architecture in languages like Java, C#, or TypeScript using frameworks like Spring Boot, ASP.NET Core, or NestJS. The course emphasizes writing unit, integration, and acceptance tests, along with implementing ports and adapters to abstract away external dependencies such as databases or APIs. Students also practice organizing monoliths with modular architecture or evolving toward microservices. By the end, learners will be able to design complex software systems that are aligned with business goals, easy to test, and robust to change.