We’ve all experienced this: the older and larger an application becomes, the harder and more expensive it gets to maintain and extend. The widely used layered architecture often falls short as a solution: direct and indirect dependencies of all layers on the database and other infrastructure components tend to blur the boundaries between layers and intertwine technical and business code.

Hexagonal Architecture places business logic at the center, isolating technical details behind interfaces (ports) and adapters. This separation allows business and technical code to be developed and tested independently.

Starting from the goals of software architecture and a critical look at traditional layered architecture, we’ll take a deep dive into Hexagonal Architecture. You’ll learn how the Dependency Rule ensures there are no dependencies from business to technical code – and how the application core can still access infrastructure when needed. Does Hexagonal Architecture actually fulfill the goals of a solid software architecture? What challenges does it introduce? How does it compare to Onion and Clean Architecture, and what synergies emerge when combined with Microservices and Domain-Driven Design?

Armed with these insights, you’ll be able to improve the quality and longevity of your software projects and respond more quickly to new requirements in the future.

This talk has been presented at:
- JUG Darmstadt
- JavaLand 2024
- JUG Berlin
- JUG Saxony Day 2025