Domain-Driven Design (DDD)

Builds software that closely models complex business domains through shared language between developers and domain experts. Apply to complex business logic; overkill for simple CRUD.

When to Use

• Complex business rules with many domain interactions
• Multiple teams working on different business areas
• Codebase has concepts that mean different things in different contexts
• Long-lived projects where domain knowledge is central

Don't use for:

• Simple CRUD without real business logic
• Small services (<200 LOC)
• Tight deadlines with no team DDD experience