PHP Developer

PHP Developer Interview Questions

PHP Developers join forces on the Back-end Developers team to write code for the server-side of web applications. 

Their primary focus is to develop back-end components that will connect applications with other (often third-party) web services while supporting the Front-end Developers by integrating their work.

PHP is no cakewalk, so look for candidates with a solid technical background and excellent coding skills. 

To source your best next hire, you may want to include an assignment to better evaluate your candidates’ skills.

Keep an eye out for candidates who:

• Demonstrate a strong passion for programming 
• Keep current with the industry by attending seminars or workshops
• Have a few side projects in the works 
• Are driven by curiosity
• Have an insatiable appetite for learning 
  

Top tip: Hire candidates willing to grow by making sure their personal career goals align with your company's mission.

Computer Science questions

• Describe the difference between an interface and an abstract class. When do you use either? 
• Describe the difference between the include() and require() functions. Give a situation where you would use either. 
• Explain the differences between PHP constants and variables. When do you use either? 
• Explain what PEAR in PHP stands for.
  

Role-specific interview questions

• Do you have experience with open source projects like Joomla, Drupal or osCommerce? 
• What do you think are the best design and coding practices?
• How can HTML, CSS, Javascript or AJAX come into play with web application design?
• Walk me through the troubleshooting process you follow when a program doesn’t run properly.
• How do you fix error types? Give specific examples.  
• What method do you follow to generate random numbers in PHP? 
• Walk me through how to get details for a browser using PHP.
• What’s the process to set cookies for a website? 
• Explain SQL. How would you create a MySql database using PHP?
• What are your primary responsibilities in the software development lifecycle?
• How would you develop and integrate plugins for PHP frameworks? 
• What features help increase user experience quality? Name any examples you find appropriate.
  

Behavioral interview questions

• What tech seminar have you attended, or would you like to attend? 
• How do you keep current with programming trends?
• When have you collaborated with developers and engineers to complete a project? What was your contribution to the team?
• What’s the most recent project you’ve worked on outside of your role within a company?