[slideshare id=39267710&doc=dgpresentation-sfdcdevelopmentbestpractices-140918191229-phpapp01]
- Apex Enterprise Patterns – Separation of Concerns
https://developer.salesforce.com/page/Apex_Enterprise_Patterns_-_Separation_of_Concerns
https://developer.salesforce.com/page/Apex_Enterprise_Patterns_-_Selector_Layer