[crackerjackmack]

As an interviewer I would be checking first for competence over most other things. The reason is that PHP itself is a landmine language that has grown up organically. I'm not hating on PHP, just stating current state of the language. (Python is full of it's own gotcha's for example)

Knowing the gotcha's of the language is important, but a competent developer also understands patterns and disciplines.

For example, it's often times that DRY is perverted into a framework that obfuscates that actual work being done and makes not only the code untestable but also debugging a nightmare. It'd okay to repeat yourself as long as it provides clarity over obfuscation. But when is too much repeating too much? How would you fix it? Refactor? Rewrite? This perversion isn't exclusive to PHP at all.

On the PHP front, in addition to frantzmiccoli's great questions I would add the following: - have you installed and used xdebug? - you ever done code profiling with xhprof ?