We are running one frontend running NGINX and several app servers running Apache2.
There are several issues we have come across but right now I'll be documenting one of them. I'll be completing this article when I get more time.
If you develop rather complex applications with Yii2, you might already be familiar with yii2-app-advanced application template. Well, the template is awesome and provides high flexibility regarding code/configuration sharing among parts of an application.