Nice article and Spring example! I noticed you put the implementation of the ports (services) in the same package as the ports itself (interfaces). You also don't call those adapters. What is the rationale behind this? What are your thoughts on a more strict separation of ports and adapters (i.e. different package or module), e.g. as suggested in https://medium.com/jeroen-rosenberg/why-ravioli-is-my-favourite-recipe-34fb16f2bc3c?