Ever tried to renovate a busy restaurant kitchen without missing a single service? That's exactly what we did with our legacy system. Using Domain-Driven Design principles, we transformed our tangled codebase into a clean hexagonal architecture - like reorganizing a kitchen around natural cooking workflows instead of just where things happened to land. You'll learn how we used DDD to identify our core business domains, establish clear boundaries between them, and gradually transform our system while keeping our 'restaurant' running at full capacity. Whether you're dealing with legacy systems, team ownership challenges, or trying to better align your code with your business domains, you'll walk away with a practical recipe for success