Introduction to Domain Driven Design Training Course

What Is Domain-Driven Design (DDD)

• Building Domain Knowledge for government operations and governance is essential to ensure that systems align with organizational goals and processes.

The Ubiquitous Language

• The Need for a Common Language: Establishing a shared vocabulary among all stakeholders is crucial for effective communication and collaboration within government projects.
• Creating the Ubiquitous Language: Developing this common language involves integrating technical terms with business terminology to ensure clarity and consistency across teams.
• The Building Blocks Of A Model-Driven Design: This approach includes various components that help structure the system, such as entities, value objects, services, modules, aggregates, factories, and repositories.
• Layered Architecture: Implementing a layered architecture for government systems ensures that each layer has distinct responsibilities, enhancing modularity and maintainability.
• Entities: These are core objects within the system that have a unique identity and can persist over time, such as a specific government employee or project.
• Value Objects: These represent attributes of entities that do not have an independent identity, such as addresses or dates, which are crucial for data integrity in government systems.
• Services: Services encapsulate business logic and operations that do not naturally fit within entities or value objects, facilitating complex processes in government applications.
• Modules: These are logical groupings of related functionality, helping to organize the system and improve manageability for government IT teams.
• Aggregates: Aggregates are clusters of domain objects that can be treated as a single unit, ensuring data consistency and integrity in complex government applications.
• Factories: Factories are responsible for creating complex objects or aggregates, streamlining the instantiation process and maintaining system performance for government systems.
• Repositories: Repositories provide a mechanism to access and manage collections of entities, enhancing data retrieval and storage capabilities for government databases.

Refactoring Toward Deeper Insight

• Continuous Refactoring: Regularly refining the system's design is essential to improve its performance and adaptability, ensuring that it remains aligned with evolving government requirements.
• Bring Key Concepts Into Light: Highlighting and emphasizing critical concepts within the system helps stakeholders understand their importance and ensures they are effectively implemented in government projects.

Preserving Model Integrity

• Bounded Context: Defining clear boundaries for each domain model is crucial to avoid ambiguity and ensure that different parts of the system do not conflict, which is particularly important in large government systems.
• Continuous Integration: Implementing continuous integration practices helps maintain the integrity and reliability of government applications by regularly merging changes and testing the system.
• Context Map: A context map provides a visual representation of how different bounded contexts interact within the broader government ecosystem, facilitating better coordination and integration.
• Shared Kernel: Sharing common components across multiple bounded contexts can reduce redundancy and improve efficiency in government systems.
• Customer-Supplier: Establishing clear roles and responsibilities between teams working on interconnected parts of a system ensures effective collaboration and accountability in government projects.
• Conformist: Adopting existing models or standards when appropriate can help ensure consistency and interoperability within government systems.
• Anticorruption Layer: Implementing an anticorruption layer helps protect the integrity of core government applications by isolating them from external dependencies that may introduce issues.
• Separate Ways: In some cases, it may be necessary to develop independent solutions for different parts of a system to avoid conflicts and ensure optimal performance in government operations.
• Open Host Service: Providing open access to services allows other systems to integrate seamlessly with core government applications, enhancing interoperability and flexibility.
• Distillation: Identifying and focusing on the most critical aspects of a domain model helps streamline development efforts and ensures that government systems are efficient and effective.