Before we build higher, let's quickly touch the foundation. You're already familiar with the core ideas, so this is just a brief refresher to set the stage.

Each Bounded Context has its own domain model and its own Ubiquitous Language, a shared vocabulary developed by the team. This ensures clarity and prevents the kind of ambiguity that leads to bugs and design flaws. The relationships between these contexts are managed through a Context Map, which acts as a blueprint for system integration.

These components don't exist in a vacuum. They're guided by a set of principles that ensure the software model remains clean, useful, and aligned with the business it serves. The central idea is that the model and the design should shape each other in a continuous cycle of refinement.

This means focusing relentlessly on the core domain. The software's structure should reflect the business domain, not just technical patterns. This is achieved through strategic design, which involves defining Bounded Contexts and their relationships, and tactical design, which deals with the building blocks inside a single context, like Entities, Aggregates, and Value Objects. This separation of concerns was a key insight from Eric Evans in his original work on the subject.

So, how do all these pieces fit together? Domain-Driven Design provides a framework for understanding a system at both a high level (strategic) and a detailed level (tactical). It's not just about code; it's about modelling complexity in a way that makes sense to everyone involved.

Understanding these foundational elements allows us to tackle more complex scenarios. It gives us a shared language and a set of tools to ensure we're building the right thing, and building it well. Now, let's quickly test that shared understanding.

With that recap complete, we're ready to explore how these concepts are applied to solve real-world problems.