I wonder how one professional developer would design the backend-part of his application.

I try to use PHP as seldom as possible and only for data serving/saving purposes.

To do so, i would create a module/class for every greater part of my application, then write some single script files which are called by javascript.

E.g:

• User clicks a "retrieve data" button
• javascript will call retrieveData.php
• retrieveData.php will create an instance of the needed class, then executes myInstance->retrieve()
• the data is returned to my JS by retrieveData.php

However, i see some disadvantages in this practice:

• I will need a single scipt file for every action, (e.g retrieveData.php, saveData.php etc)
• I need a man-in-the-middle step: from JS to my single script, to my classes

How are modern applications designed to accomplish what i need to do?