Using the internet, search for an enterprise company (i.e. Amazon) that you feel follows this enterprise architecture and consider the implications of each function represented.  For each function in this diagram, define the purpose and interaction with other function, give examples.  Define and discuss credible attack surfaces for each function, if any. Does the function include interactions with third party systems? If so, should they be trusted at the same level as the internal systems.  Discuss threat agents and what targets may be of interest.