Chapter 5 Designing the integration Layer • Maximize business value: Microservices over monolithic service architecture will provide maximum business value by breaking down functionality to the most basic level and then abstracting the related services. • Lower the total cost of ownership and management: Microservices architecture will increase the decoupling and separation of concern, hence the code base would be easier to manage as each service in the application would be independent of other services and thus it would be easier to add new feature or functionality to the platform. Conversely, in monolithic architecture, adding a new functionality will require smoke testing of the whole application. • Interface details: Go through the interface details, for example, API’s operations, inputs, outputs, and underlying types such as XML or JSON, which helps you to integrate the existing or third-party APIs with the DXP application. • Data requirements: A DXP consumes data in any format such as XML or JSON using any service protocol such as RESTLESS-SOAP or JMS, but interacts in RESTFUL-JSON within an application. RESTFUL-JSON interaction makes the application’s integration layer flexible and lightweight. REST services are architectural style. REST uses HTTP protocol and HTTP methods like GET, POST, PUT, and DELETE to communicate between client (Angular application) and server (integration) application; whereas, as SOAP is a message exchange style between client and server, SOAP services are Remote Procedural Call (RPC) architecture style, which would have service metadata (i.e., contracts) to communicate between client and server. • Restless: These services work with resources as well as its operations such as PUT, POST, DELETE etc. You need to identify the services and operations attached to REST Service, for example, operations such as SaveTransation(), GetTransaction(), DeleteTransaction(), UpdateTransaction() on transaction services. A service contract has to be shared with the client; the client will use these details to call the services. 151