[VDBUH2026] George Patrașcu - Ports, Adapters, and Other Ways to Stop Breaking Your Business Logic

Your business logic shouldn’t care whether it’s talking to a SQL database, a Kafka topic, or a REST API — but in most codebases, it does. In a microservice architecture, this coupling becomes especially painful: as services evolve and API versions change, you end up touching business logic just to keep up with infrastructure churn. In this talk, we’ll explore Hexagonal Architecture (Ports & Adapters) as a practical answer to this problem. We’ll start with the “why”: not to dismiss traditional layered architectures — they solve real problems, and it’s the model we use across many of our own services — but to examine the specific caveats that emerge as systems grow. Where does coupling infrastructure concerns to business logic start to hurt? Hexagonal Architecture doesn’t throw layering out the window; it refines it, offering targeted solutions to those exact pain points. From there, we’ll walk through the core concepts of the pattern — ports, adapters, and the application core. But this won’t be a textbook walkthrough. Everything you’ll see is grounded in real production experience. We’ll share the challenges we ran into, the mistakes we made, and the tradeoffs we had to navigate — including the pragmatic vs. dogmatic decisions that come up constantly in practice (should your ORM bleed into your domain model? It depends). You’ll leave with: – A clear mental model of Hexagonal Architecture and when it’s worth reaching for – Concrete code examples of ports and adapters in action, written in C# – Different approaches to structuring your project (and when to choose each) – An honest look at the tradeoffs — including when not to use this pattern Whether you’re building a new service or wrestling with an existing one, this talk will give you practical tools to make your business logic more resilient, testable, and independent of the infrastructure around it.