What a Peach Tree Can Teach You About Domain‑Driven Design

In the article "Reasons for the Rise of DDD and Its Relationship with Microservices," an example of studying a peach tree is presented. If we study a peach tree, we can divide it into organs—root, stem, leaf, flower, fruit, seed—each representing a domain, which can be further split into subdomains, core domains, generic domains, and supporting domains.

Looking at the picture, if studying the peach tree is our business, how can we research it more quickly and effectively? A middle‑school textbook would approach it as follows:

Step 1: Identify the research object, i.e., the domain—here, a peach tree.

Step 2: Based on certain dimensions, split the object into organs, which can be categorized as nutritional organs (root, stem, leaf) and reproductive organs (flower, fruit, seed). These become our subdomains.

Step 3: Further divide the subdomains to locate the core domain, generic domain, and supporting domain. After identifying the core domain, each subdomain can be broken down into organizations such as protective, nutritional, and conduit organizations, effectively continuing the domain‑to‑subdomain refinement.

Step 4: Organizations can be further divided into cells, for example, root hair cells, vessel cells, and so on.

Whether to continue splitting cells depends on the specific business context; often the smallest level corresponds to entities, aggregates, aggregate roots, and value objects in DDD.

Key terminology:

Domain: A specific part of the business, such as sales, logistics, or supply chain in e‑commerce. Domains define the bounded context within which a domain model is built.

Subdomain: A further division of a domain, which can be recursively split. In the peach‑tree analogy, organs become subdomains, and deeper layers like tissues or cells become sub‑subdomains.

Core Domain: The most critical part of the business that provides competitive advantage and profit, e.g., the sales system in an e‑commerce platform.

Generic Domain: Non‑core functionalities that are reusable across multiple domains, such as authentication or logging.

Supporting Domain: Functions that support the business but are not core or generic, like payment or logistics services, which may be outsourced.

Why Divide Core, Generic, and Supporting Domains?

Identifying the core domain focuses resources on the business’s competitive edge, while generic domains handle shared concerns, and supporting domains cover necessary but non‑differentiating functions. This classification helps allocate budget, time, and effort appropriately, ensuring that strategic focus aligns with business goals.

In summary, distinguishing core, generic, and supporting domains enables companies to prioritize development effort, optimize resource allocation, and align technical architecture with strategic business objectives.

Source: https://www.cnblogs.com/Courage129/p/14853600.html