Hiring - Php interview questions

For some time, I have had an interest in php interview questions (even developed a site with that in mind) to make sure I get the right person for the job (since I'm no techie). I guess I'm wondering what have other employers done in the past?

Thanks

Garry Ponus

Had a developer or two to sit in and ask some questions.

thanks. I guess I'm wondering how diverse php is. If someone says they are a php developer, is that all that's needed or are there certain aspects one should look for?

Depends on what you're looking for. PHP programmers are a dime a dozen, so finding one is easy. On the other hand, finding a *good* PHP programmer is a considerably more difficult task. Lots of people tend to fudge their resumes and a face-to-face interview usually reveals how much they really know.

Most of the PHP guys that I've interviewed can throw together a quick website that they can maintain themselves (main issue that I have is that most don't know how to escape strings correctly and rely on magic quotes). Finding one that can work in a team environment and has some ideas of good software development practices is a little more difficult. Anyone else have similar experiences with finding good PHP programmers?

There are areas one can specialize in - regular expressions, OOP, and interface design, for instance - but it's mostly about general web development. That requires additional knowledge of how to write HTML, CSS, and Javascript. Almost everything requires a database of sorts so that means knowledge of generic SQL as well as more specific stuff with MySQL or MS SQL or PostgreSQL or the current NoSQL flavor of the month. Venturing outside development per se there's more technical stuff like cloud computing and project management, which can be very helpful to know even if one wants to spend most of their time simply programming.

With PHP there's also the topic of security - moreso than with other languages. The web is complicated and PHP doesn't try to hide much of that from you. SQL and XSS injection are the two very big and very smelly elephants in the room; PHP has some settings (which are finally going away, thankfully) which make writing code easier but much less safe, and developers used to relying on those can be hard to retrain to do things right; knowledge of HTTP itself leads to more understanding of problems like how cookies are insecure and that form information and file uploads are entirely untrustworthy.

If someone says they're a PHP developer that's according to their own beliefs. If they're making a site then they'll probably call themselves a "PHP developer", regardless of how much they know or don't know or how long it's been or whether their idea of development is copy/pasting code from the Internet.

[edit] I lurk a few forums, most of which include a section for (or are entirely focused on) PHP. Every day I see somebody who is doing something badly: the code is insecure, poorly designed, and/or incorrectly written. Like Scorpy said, there are tons of "PHP developers" out there but there are very few that I would consider hiring. Like <5% of them.