16 Nov 2023
Expert
Example 1:
Key concepts and strategies for strategic design in e-commerce using DDD:
-
Bounded Contexts:
- Identify and define bounded contexts for different subdomains within the e-commerce system. For example, you might have separate bounded contexts for inventory management, order fulfillment, customer management, and product catalog.
-
Ubiquitous Language:
- Establish a common, shared language (ubiquitous language) between business stakeholders and development teams. This ensures that everyone involved in the project has a consistent understanding of the domain concepts. For example, terms like "shopping cart," "order," and "payment" should have clear and agreed-upon meanings.
-
Aggregate Roots:
- Identify aggregate roots for each bounded context. In an e-commerce system, examples of aggregate roots could be "Order," "Product," and "Customer." These aggregate roots encapsulate and protect the integrity of the underlying entities and value objects within them.
-
Context Mapping:
- Define the relationships and interactions between different bounded contexts using context mapping. This helps manage the boundaries between subdomains and handle communication and data exchange effectively. For example, the interaction between the order management context and the payment context needs to be well-defined.
-
Strategic Patterns:
- Apply strategic patterns such as Shared Kernel, Customer/Supplier, and Conformist to manage dependencies and integration points between different bounded contexts. For instance, a Shared Kernel might involve sharing a common set of classes or interfaces between two contexts that collaborate closely.
-
Anti-corruption Layer:
- Implement anti-corruption layers to translate and adapt data between different bounded contexts, preventing the corruption of the domain model. This is crucial when integrating with external systems or services, such as payment gateways or shipping providers.
-
Event Storming:
- Use event storming to model and capture important domain events within the e-commerce system. Events can represent state changes or significant occurrences in the system, and they play a key role in event-driven architectures.
-
CQRS (Command Query Responsibility Segregation):
- Consider adopting CQRS to separate the command (write) and query (read) responsibilities within the system. This can lead to more scalable and maintainable solutions, especially in scenarios where the read and write models have different requirements.
-
Domain Services:
- Identify and implement domain services for business logic that doesn't naturally fit into entities or value objects. For example, in e-commerce, you might have a pricing service or a shipping service that encapsulates complex pricing or shipping calculations.
-
Continuous Refinement:
- Recognize that strategic design is an iterative process. As the understanding of the domain deepens or as business requirements evolve, be prepared to refine and adjust the strategic design of the system.
By applying these strategic design principles and patterns in DDD, you can create a flexible, scalable, and maintainable e-commerce system that accurately reflects the complexities of the business domain. Keep in mind that DDD is not a one-size-fits-all approach, and the specific design decisions should be driven by the unique characteristics and requirements of the e-commerce domain you are working with.
+---------------------------------+
| E-Commerce System |
| |
| +------------------------+ |
| | Bounded Contexts | |
| | - Inventory | |
| | - Order Fulfillment | |
| | - Customer Management| |
| | - Product Catalog | |
| +------------------------+ |
| |
| +------------------------+ |
| | Ubiquitous Language | |
| | | |
| | Shared Terms: | |
| | - Shopping Cart | |
| | - Order | |
| | - Payment | |
| +------------------------+ |
| |
| +------------------------+ |
| | Aggregate Roots | |
| | - Order | |
| | - Product | |
| | - Customer | |
| +------------------------+ |
| |
| +------------------------+ |
| | Context Mapping | |
| | - Relationships | |
| | - Integration Points | |
| +------------------------+ |
| |
| +------------------------+ |
| | Strategic Patterns | |
| | - Shared Kernel | |
| | - Customer/Supplier | |
| | - Conformist | |
| +------------------------+ |
| |
| +------------------------+ |
| | Anti-corruption Layer| |
| +------------------------+ |
| |
| +------------------------+ |
| | Event Storming | |
| +------------------------+ |
| |
| +------------------------+ |
| | CQRS | |
| +------------------------+ |
| |
| +------------------------+ |
| | Domain Services | |
| | - Pricing Service | |
| | - Shipping Service | |
| +------------------------+ |
| |
| +------------------------+ |
| | Continuous Refinement | |
| +------------------------+ |
| |
+---------------------------------+
Please note that this ASCII diagram is a high-level representation and doesn't capture the full complexity of the concepts discussed.
Example 2:
Key concepts and strategies for strategic design in social media using DDD:
-
Bounded Contexts:
- User Management Context: This context could handle user registration, authentication, and profile management.
- Social Network Context: This context might be responsible for handling friend requests, posts, comments, and other social interactions.
- Notification Context: This context could manage notifications such as likes, comments, and friend requests.
-
Aggregates:
- User Aggregate: This could encapsulate user-related information like username, email, password, and profile details. It might also include logic for authentication.
- Post Aggregate: This could include post content, author information, comments, likes, and other related information.
- Friendship Aggregate: This could manage the relationships between users, handling friend requests, approvals, and removals.
-
Ubiquitous Language:
- Establish a common language that is used consistently across the development team and stakeholders. For example, terms like "User," "Post," "Friend Request," and "Notification" should have clear and agreed-upon meanings.
-
Context Mapping:
- Define how different bounded contexts interact with each other. For example, the User Management Context might need to communicate with the Social Network Context to create or update user profiles.
-
Anti-Corruption Layer:
- Implement an anti-corruption layer to ensure that the models and logic of one bounded context are not corrupted by the models of another. This is important when integrating different contexts to avoid conflicts and inconsistencies.
-
Context Independence:
- Make each bounded context as independent as possible. This allows teams to work on different contexts concurrently without interfering with each other.
-
Event Storming:
- Use event storming to model the flow of events and commands within the system. For instance, events like "UserRegistered," "PostCreated," or "FriendRequestAccepted" can be identified and used to drive the design.
-
Strategic Vision:
- Have a strategic vision for the evolution of the system. For a social media platform, this might include future features like real-time updates, multimedia sharing, or advanced recommendation algorithms.
-
Continuous Collaboration:
- Encourage continuous collaboration between domain experts, developers, and other stakeholders to refine and evolve the strategic design as the understanding of the business domain deepens.
-
Technology Alignment:
- Align the chosen technologies with the strategic design. For example, if real-time updates are a part of the strategic vision, choose technologies that support this requirement.
+---------------------------------+
| Social Media System |
| |
| +------------------------+ |
| | Bounded Contexts | |
| | - User Profiles | |
| | - Posts and Feeds | |
| | - Notifications | |
| | - Messaging | |
| +------------------------+ |
| |
| +------------------------+ |
| | Ubiquitous Language | |
| | | |
| | Shared Terms: | |
| | - User | |
| | - Post | |
| | - Feed | |
| | - Notification | |
| +------------------------+ |
| |
| +------------------------+ |
| | Aggregate Roots | |
| | - User | |
| | - Post | |
| | - Notification | |
| +------------------------+ |
| |
| +------------------------+ |
| | Context Mapping | |
| | - Relationships | |
| | - Integration Points | |
| +------------------------+ |
| |
| +------------------------+ |
| | Strategic Patterns | |
| | - Shared Kernel | |
| | - Customer/Supplier | |
| | - Conformist | |
| +------------------------+ |
| |
| +------------------------+ |
| | Anti-corruption Layer | |
| +------------------------+ |
| |
| +------------------------+ |
| | Event Storming | |
| +------------------------+ |
| |
| +------------------------+ |
| | CQRS | |
| +------------------------+ |
| |
| +------------------------+ |
| | Domain Services | |
| | - Messaging Service | |
| | - Notification Service| |
| +------------------------+ |
| |
| +------------------------+ |
| | Continuous Refinement | |
| +------------------------+ |
| |
+---------------------------------+
Please note that this ASCII diagram is a high-level representation and doesn't capture the full complexity of the concepts discussed.
domain-driven-design-ddd
strategic-design
