This post is a follow-up to the question/discussion-point Darrel Miller has started here. The question is that in the REST world, what is coupling and how we can achieve de-coupling. Although this post can be read independently, it is best to start with reading his post first. We discuss three models: server-concern, client-concern and mixed-concern. Each of these are valid patterns but they each come with its own anti-pattern to be aware of.