Have you ever wondered why some software seems to be disconnected or even constantly fighting the business, while other systems grow naturally from it? The answer lies in domain modelling.

This talk explores the importance of continuously defining and modelling domain boundaries to design adaptable and resilient software systems. You'll leave with a clear understanding of what a subdomain is, how it differs from a bounded context and a service boundary, and why grasping this distinction is fundamental to good architecture.

Modelling domain boundaries with stakeholders is essential for building good software. We will explain how they are related to, yet distinct from, service boundaries and bounded contexts. We'll also present why designing and continuously adjusting these boundaries based on feedback is a good habit for creating software that aligns with the business and generates new opportunities.

We won't shy away from the complex challenges, either: the resistance to change, the disconnect between an ideal future and the weight of legacy systems, and the struggle of getting a group to agree on what a "customer" even means.

You'll get practical insights and design heuristics on how to collaboratively model these boundaries using techniques like Big Picture EventStorming, Domain Storytelling, Wardley Mapping, and Context Mapping.