Watching Simon Brown now &amp; will look at his book too, thanks.<p>To take the current project, I have a CMS, Salesforce and ExactTarget. I&#x27;m writing the glue to automate taking new content from the CMS, finding SF users with the right permissions to see it, and emailing it to them via ExactTarget.<p>All good &amp; working until... do I model it as 3 objects? Which object is responsible for creating the DataTable at ExactTarget (populated with SF data)? How is data going to be passed around cleanly between my representations of all 3 services? Or should I represent the system more abstractly as EmailToSend, EmailContent and use all three services within these classes?