implementatielaag

Implementatielaag is the Dutch term for the layer in a software architecture that contains concrete implementations of interfaces defined by higher-level layers. It is part of a multi-layer design and often overlaps with what is called the infrastructure or persistence layer in other contexts. The implementatielaag typically hides technology-specific details from the domain and presentation layers.

The responsibilities of the implementatielaag include providing concrete classes that perform persistence, communication with external systems, file I/O, and other infrastructure tasks. It may include repositories or gateways that implement domain interfaces, data mappers that convert between persistence models and domain models, API clients, message handlers, and adapters that integrate with external services. The layer may also handle cross-cutting concerns such as logging, transactions, and security when applied consistently.

In typical designs, higher layers define interfaces or ports, while the implementatielaag provides the adapters that fulfill those contracts. This separation supports testability, the replacement of technology stacks, and adherence to the dependency inversion principle. Patterns commonly associated with it include repositories, gateways, adapters in hexagonal architecture, and anti-corruption layers to isolate the domain from external models.

Examples: in Java with Spring, repository implementations using JPA or JDBC; in .NET, data access providers; in microservice architectures, API adapters and message brokers are often implemented here.

Notes: the term is primarily Dutch-language; in English-language literature, similar concepts may be described as the infrastructure layer or persistence layer, or as adapters in hexagonal architecture. The exact boundaries can vary by project and methodology.