,---------------------------------------------------.                                                                                                                                           
                                                                                                                            |== Customer                                        |                                                                                                                                           
                                                                                                                            |---------------------------------------------------|                                                                                                                                           
                                                                                                                            |A customer of the bank, with personal bank accounts|                                                                                                                                           
                                                                                                                            |                                                   |                                                                                                                                           
                                                                                                                            `---------------------------------------------------'                                                                                                                                           
                                                                                                                                                                                                                                                                                                                            
                                                                                                                                                                                                                                                                                                                            
,--------------------------------------------------------.  ,----------------------------------------------------------------------------------.   ,----------------------------------------------------------------------------------------------------.   ,--------------------------------------.                        
|== Web Application                                      |  |== Single-Page App                                                                |   |== Mobile App                                                                                       |   |== E-Mail System                      |                        
|--------------------------------------------------------|  |----------------------------------------------------------------------------------|   |----------------------------------------------------------------------------------------------------|   |--------------------------------------|                        
|                                                        |--|                                                                                  |   |                                                                                                    |   |The internal Microsoft Exchange system|                        
|Delivers the static content and the Internet banking SPA|  |Provides all the Internet banking functionality to customers via their web browser|   |Provides a limited subset of the Internet banking functionality to customers via their mobile device|   |                                      |                        
|                                                        |  |                                                                                  |   |                                                                                                    |   `--------------------------------------'                        
`--------------------------------------------------------'  `----------------------------------------------------------------------------------'   `----------------------------------------------------------------------------------------------------'                                                                   
                                                                                                                                                                                                      |                                                                                                                     
                                                                                         ,--------------------------------------------------------------------------------.   ,-----------------------------------------------.                                                                                             
                                                                                         |== Database                                                                     |   |== API Application                             |   ,----------------------------------------------------------------------------------------.
                                                                                         |--------------------------------------------------------------------------------|   |-----------------------------------------------|   |== Mainframe Banking System                                                             |
                                                                                         |                                                                                |   |                                               |   |----------------------------------------------------------------------------------------|
                                                                                         |Stores user registration information, hashed auth credentials, access logs, etc.|---|Provides Internet banking functionality via API|-- |Stores all of the core banking information about customers, accounts, transactions, etc.|
                                                                                         |                                                                                |   |                                               |   |                                                                                        |
                                                                                         `--------------------------------------------------------------------------------'   `-----------------------------------------------'   `----------------------------------------------------------------------------------------'