Domain-Driven Design (DDD) is a software development approach that emphasizes the importance of the domain in building systems. Key concepts include ubiquitous language, bounded contexts, and various tactical design elements such as entities, aggregates, and value objects. The document also references additional topics like CQRS and event sourcing, along with useful resources for further reading.

1. Domain Driven Design

2. What is DDD
• DDD is an approach to building
software with a focus on
the domain.

3. Clinic System
Patient
Visit
Clinic

4. Lets Code
Anemic Model

5. Rich Model
(Entity)

6. Strategic Design
• Ubiquitous Language
• Bounded context
• Context Maps

7. Ubiquitous Language
• Ubiquitous language is a model that
acts as a universal language to help
communication between software
developers and domain experts.
• To produce a clear Ubiquitous
Language you will have to understand
more of the business.

8. Bounded context
• Is a defined part of software where
particular terms, definitions and rules
apply in a consistent way.
• Payment Context
• Ordering Context
• Patient Registration Context

9. Context Maps
• Context Maps help in
understanding the whole project,
being able to show the
relationships between the
different Bounded Contexts.

10. Tactical Design
• Entities
• Aggregates
• Value Objects
• Repositories
• Factories
• Services
• Events

11. Entity
• Is a plain object that has an
identity (ID) and is potentially
mutable
Patient
Clinic
Doctor
Employee

12. Aggregates (Aggregate root)
• Aggregate root is an entity that
binds together with other
entities
• Actually a part of aggregate
Visit
Medicines
Procedures
Lab tests
Radiations

13. Value Objects
• Value objects are immutable.
• They have no identity (ID) like we
found in entity.
• Two value objects can be
considered equal if both of them
have the same type and the
same attributes
Email
Address
Money
Address

15. Repositories
• To deal with the storage

16. Factories
• A Factory is an object that has
the single responsibility of
creating other objects

17. Services
• a home for operations that don’t
quite fit into an aggregate root
• Application Services
• Domain Services

18. Events
• A Domain Event represents
something that has happened in
the domain
• OrderCreated
• OrderDeleted

19. Further topics
• CQRS
• Event Sourcing

20. Ref
• https://thedomaindrivendesign.io/what-is-ddd/
• https://www.amazon.com/Hands-Domain-Driven-Design-NET-
ebook/dp/B07C5WSR9B
• https://dzone.com/articles/ddd-part-ii-ddd-building-blocks
• https://culttt.com/2014/12/24/factories-domain-driven-design/