Arquitectura limpia y Diseño dirigido por el Dominio

Referencias:

The clean architecture, Robert C. Martin
Implementing the Onion Architecture in PHP, Por Kristofer Wilson
The clean architecture in PHP, presentación por Kristofer Wilson
Onion architecture and Zend framework, por Igor Vorobiov
The onion architecture, por Jeffrey Palermo
Well designed application arquitectures, por Jeremy Bush
Building an object model, por Benjamín Eberlei
Clean architecture using DDD layering in PHP, presentación por Leonardo Proietti

Lecturas sobre Diseño dirigido por el dominio

Domain Driven Design, por Chris Peters
Domain-Driven Design and MVC Architectures, por Federico Cargnelutti
Domain Driven Design and Development In Practice, por Srini Penchikala
Domain-driven Design Example, por Mirko Sertic
Domain-driven Design - Overview and building blocks, por Mirko Sertic

Una explicación de DAO pattern
Decoupling models from the database: Data Access Object pattern in PHP, por Jani Hartikainen

Cómo diferenciar entre Entidades y Value Objects
What is the difference between Entities and Value Objects?, por Philip Brown
DDD: Help me further understand Value Objects and Entities, pregunta en StackOverflow
A Discussion on Domain Driven Design: Entities. por Joe Ocampo

A Discussion on Domain Driven Design: Value Objects. por Joe Ocampo

Implementaciones de seguridad y DDD
Don't do role based authorization checks