What is the design pattern of WordPress Core? As this Stack Overflow question shows, WordPress does not follow the MVC pattern; however, developers can write plugins and themes that follow MVC. But my question pertains exclusively to WordPress Core, not to any additional add-ons, themes, extensions, plugins, or forked projects that may or may not follow an MVC pattern.
If WordPress Core does not follow an MVC design, then what design pattern does it follow?
Spaghetti with meatballs
The term “spaghetti with meatballs” is a pejorative term used in
computer science to describe loosely constructed object-oriented
programming (OOP) that remains dependent on procedural code. It may be
the result of a system whose development has included a long life
cycle, language constraints, micro-optimization theatre, or a lack of
coherent coding standards.
It also has a bit of macaroni mixed in…
http://en.wikipedia.org/wiki/Spaghetti_code#Spaghetti_with_meatballs