Webnodes CMS was created from scratch starting in 2005, based upon our experiences of two previous CMS generations and hundreds of CMS projects on those previous CMS'.
The Webnodes CMS has a modern n-tier architecture in which the presentation, business logic and the data management are logically separated layers in the code.
One of the fundamental rules of an n-tier architecture is that all communication from the presentation/client layer is routed through the business layer, and the client can't communicate directly with the data access layer. For a content management system, access to the correct content is a crucial part of the system. An n-tier simplifies both our job in developing the solution, but it also makes it easier for implementation developers to be productive. When a request for data is sent to the business layer, the business layer filters out data the current session(user) doesn't have access to.
A simplified view the Webnodes CMS architecture