Decoding DDD: A Three-Tiered Approach to Django Projects

Dive into the world of Domain-Driven Design (DDD) and learn how to apply its principles to your Django projects, exploring the relationships between domain, data, and infrastructure layers.

Key takeaways
  • Context boundaries should align with the boundaries of microservices or high-level modules in a modular monolith.
  • DDD patterns can be used in Django projects to improve code structure and maintainability.
  • Domain layer should be independent of data access layer, and bounded contexts should not overlap.
  • Value objects are objects that can be identified by the composition of its values, and are used to encapsulate complex business logic.
  • Aggregate patterns resemble a hierarchy of entities sharing transactional consistency.
  • Anemic domain models lack significant behavior and contain no primary data, whereas rich domain models encapsulate complex business logic.
  • Ubiquitous language is the shared language between developers and business experts, and is crucial for understanding bounded contexts.
  • Deprecate the use of Django models as aggregates, and instead use domain models as segregators of concern.
  • Repository interfaces can be used as ports, and their implementations as adapters, to decouple domain models from database representations.
  • Tactical patterns such as the domain service pattern can be used to encapsulate complex business logic.
  • Some bounded contexts may require additional complexity and patterns, such as saga or two-phase commit, to maintain transactional integrity.
  • Domain models should be designed to encapsulate complex business logic, and aggregate roots to handle state transitions.
  • Value objects can be used to encapsulate complex business logic, such as those related to money and email.
  • Domain services can be used to encapsulate business logic that does not belong to single aggregate or value object.