domain-driven-design

name	domain-driven-design
description	DDD tactical and strategic patterns. Use for complex domains.

Domain-Driven Design (DDD)

DDD is a software design approach focusing on modeling software to match a domain according to input from that domain's experts. It is essential for tackling high complexity in the heart of software.

When to Use

• Complex business domains (e.g., Insurance, Banking, Logistics) where logic is intricate.
• When there is a communication gap between developers and business experts.
• decomposing a Monolith into Microservices (defining boundaries).

Quick Start

// Aggregate Root
public class Order {
    private OrderId id;
    private Money totalAmount;
    private OrderStatus status;
    private List<OrderItem> items; // Aggregates items

    // Behaviors (Rich Model), not just Getters/Setters
    public void addItem(Product product, int quantity) {
        if (this.status != OrderStatus.DRAFT) {
            throw new DomainException("Cannot modify confirmed order");
        }
        this.items.add(new (product, quantity));
        recalculateTotal();
    }

       {
         (items.isEmpty())   ();
        .status = OrderStatus.CONFIRMED;
        
        DomainEvents.publish( (.id));
    }
}