Models and Service Layers, Hemoglobin and Hobgoblins https://www.slideshare.net/rosstuck/models-and-service-layers-hemoglobin-and-hobgoblins

Рефакторинг PHP-кода с применением DDD https://www.youtube.com/watch?v=9xoP9GCUoDU

How to publish and handle Domain Events http://www.kamilgrzybek.com/design/how-to-publish-and-handle-domain-events/