Strong knowledge of PHP web frameworks and CMS such as WordPress and Opencart would also be great.
Familiarity with SQL/NoSQL databases and their declarative query languages
Integration of multiple data sources and databases into one system Familiarity with limitations of PHP as a platform and its workarounds
Understanding the fully synchronous behavior of PHP
Understanding of MVC design patterns.
Understanding fundamental design principles behind a scalable application
User authentication and authorization between multiple systems, servers, and environments
Creating database schemas that represent and support business processes
Strong knowledge of the common PHP or web server exploits and their solutions
Knowledge of object oriented PHP programming