Domain driven design

For small and uncomplicated software products DDD, like other architecture design principles, is not so important. But narrow subject areas with complex specifics require careful thought at the highest level. DDD suggests creating subject area models that contain complex business logic. ## Model A model is a system of abstractions that describes the individual characteristics of a domain. Like a physical model that simplifies the understanding and study of an object, it helps to solve problems related to a given domain. ## Domain Modeling Domain modeling is a technique used in software development, particularly in the context of domain-driven design (DDD), to represent the basic concepts, rules, and relationships in a particular business domain. ## Aggregate Aggregates are associations of entities and value objects with clearly delineated boundaries. You can think of an aggregate simply as a group that allows you to refer to all the elements within it at once. For example, instead of making the command "slice apple" and repeating it n times, you could aggregate all apples into the group "apples" and apply the command "slice" to that group. ## Service Services are functions that are not attached to entities or value objects. Roughly speaking, an action in itself. ## Repositories Repositories are services that use a global interface to provide access to all entities and value objects that reside in a particular group of aggregates. For example, we can consider the "cut" command to be a repository when it is applied to the "fruit" aggregate group, which includes the aggregates "apples", "pears", and "bananas". Using the "Domain driven design" approach when designing software architecture and complex corporate information systems makes it easier to maintain changes in the project and more efficient to test new releases.