My project is organized in layers like * Configuration * Controller * Service * Repository * Domain Our REST Controller is in the Controller layer. We need to connect to another API via REST calls and I'm not sure if I should make a new Controller or do it in the Service layer. I'm going to implement the REST calls with this http://docs.spring.io/spring-framework/docs/4.0.x/javadoc-api/org/springframework/web/client/RestTemplate.html The way our API will be used is like this: - REST call is made that goes through our REST endpoint. - Our REST endpoint will call the third party API (either by calling another controller method or a service method). - We will then do a conversion between our format and the third party format - Then we will return the JSON of our format back to the client