Advanced Architecture (The Enterprise Core 🏢)

For when MVC is not enough.

Patterns

1. DDD (Domain-Driven Design)

• •Aggregates: Cluster of objects treated as a unit (e.g., Order + OrderLines).
• •Value Objects: Objects defined by attributes, not ID (e.g., Money, EmailAddress). Immutability is key.
• •Bounded Contexts: Sales context vs Inventory context. Do not share models directly.

2. CQRS (Command Query Responsibility Segregation)

• •Write Side: CreateInvoiceCommand -> invoices table.
• •Read Side: InvoiceReadModel (Optimized JSON column or separate ElasticSearch index).
• •Benefit: Read performance does not block Write complexity.

3. Event-Driven

• •Domain Events: OrderPlaced (Past Tense).
• •Listeners: SendEmail, UpdateInventory, NotifySlack.
• •Decoupling: The Order Service doesn't know about Slack.