DDD - Subdomain & Bounded Context

 Example:

Domain: E-commerce

• Subdomain: Order Management

• Bounded Contexts:

1. Payment Processing

• Cohesive Bounded Context: Transaction Authorization, Billing, Fraud Detection

2. Customer Management

• Cohesive Bounded Context: Customer Registration, Account Management, Customer Support

3. Inventory Management

• Cohesive Bounded Context: Product Catalog Management, Stock Keeping, Replenishment

4. Shipping and Logistics

• Cohesive Bounded Context: Carrier Integration, Shipping Methods, Package Tracking

5. Returns and Refunds

• Cohesive Bounded Context: Return Authorization, Refund Processing, Reverse Logistics

 Let's explore some examples:

1. Payment Processing:

• This cohesive bounded context focuses on handling the payment aspects of order management.
• Concepts within this context include payment authorization, transaction processing, fraud detection, and payment reconciliation.
• Rules and processes within this context govern how payments are verified, processed, and reconciled with order information.

2. Customer Management:

• This cohesive bounded context deals with managing customer-related aspects of order management.
• Concepts within this context include customer registration, authentication, account management, and customer support.
• Rules and processes within this context focus on managing customer accounts, preferences, and interactions throughout the order lifecycle.

3. Inventory Management:

• This cohesive bounded context focuses on managing inventory-related aspects of order fulfillment.
• Concepts within this context include product catalog management, inventory tracking, stock keeping, and replenishment.
• Rules and processes within this context govern how inventory levels are monitored, products are cataloged, and stock is managed to fulfill orders efficiently.

4. Shipping and Logistics:

• This cohesive bounded context deals with managing shipping and logistics aspects of order fulfillment.
• Concepts within this context include carrier integration, shipping methods, package tracking, and delivery management.
• Rules and processes within this context focus on selecting shipping methods, generating shipping labels, tracking shipments, and managing delivery logistics.

5. Returns and Refunds:

• This cohesive bounded context focuses on handling returns and refunds for orders.
• Concepts within this context include return authorization, refund processing, restocking, and reverse logistics.
• Rules and processes within this context govern how returns are initiated, refunds are processed, and returned items are restocked or disposed of.

 

Can each bounded context be a microservice???

While each cohesive bounded context represents a distinct area of functionality within the broader "Order Management" domain, whether each one should be implemented as a microservice depends on various factors such as the system's architecture, scalability requirements, team structure, and deployment strategy. Here are some considerations:

1.     Granularity: Microservices are typically smaller, independently deployable units of functionality. Depending on the complexity and size of each cohesive bounded context, it may be appropriate to implement each one as a microservice. However, if a cohesive bounded context is relatively simple or tightly coupled with other contexts, it may be more practical to implement it as part of a larger microservice.

2.     Autonomy: Microservices should be autonomous, meaning they can be developed, deployed, and scaled independently. If each cohesive bounded context requires independent development, deployment, or scalability, implementing it as a microservice may be beneficial to achieve greater autonomy.

3.     Team Ownership: Microservices are often aligned with cross-functional teams, where each team owns one or more microservices. If the development and maintenance of a cohesive bounded context align well with a specific team's expertise and responsibilities, implementing it as a microservice may facilitate team ownership and autonomy.

4.     Integration Complexity: Microservices communicate with each other via APIs, which introduces integration overhead. If the cohesive bounded contexts need to interact frequently or share data extensively, implementing them as separate microservices may introduce complexity in managing inter-service communication and data consistency.

5.     Operational Overhead: Microservices introduce operational complexity, such as service discovery, monitoring, and deployment automation. If the benefits of implementing each cohesive bounded context as a microservice outweigh the operational overhead, then microservices may be a suitable architectural choice.

In summary, while each cohesive bounded context represents a potential candidate for a microservice, the decision to implement it as such should be based on factors such as granularity, autonomy, team ownership, integration complexity, and operational considerations. Careful analysis and consideration of these factors are essential to determine the most appropriate architectural approach for your system.