PHP Developer Interview Questions

PHP Developers write server-side web applications using Hypertext Preprocessor (PHP) scripting language. They are tasked with developing and coding back-end components and connecting applications to other web services. PHP Developers also assist front-end developers to ensure their work integrates into the application.

Whether you're a job seeker preparing to be interviewed for the role of PHP Developer or an employer preparing to interview candidates for PHP Developer position, these PHP Developer interview questions will help you prepare yourself for the job interview session.

PHP Developer Interview Questions

Below are a list of some skill-based PHP Developer interview questions.

1. What PHP frameworks do you have experience with?
2. How do you develop your design concepts for new web applications?
3. Describe your process for testing code before deploying it to the live site.
4. What front-end technologies are you most familiar with?
5. What server-side web application are you most proud of developing?
6. Tell us about your portfolio or if possible, show us what you have done with PHP.
7. What’s the most recent project you’ve worked on outside of your role within a company?
8. What do you think is the most difficult part of developing server-side logic?
9. What is your process for identifying and resolving bugs in existing code?
10. If a project requires you to use a new version of PHP, how would you determine if it is stable and safe to use?
11. How well do you work with other technical teams, such as those that use Java or JavaScript?
12. Do you have experience working with large code bases?
13. Do you have any experience with LAMP/WAMP/XAMPP?
14. When would you use an object-oriented programming (OOP) approach to coding?
15. We want to ensure that our code is secure. What is the process you would use to perform a code audit?
16. Do you have experience with open source projects like Joomla, Drupal or osCommerce? 
17. Tell me some of the disadvantages of PHP
18. What do you think are the best design and coding practices?
19. What are the rules for naming a PHP variable?
20. How can HTML, CSS, Javascript or AJAX come into play with web application design?
21. How does the ‘foreach’ loop work in PHP?
22. Walk me through the troubleshooting process you follow when a program doesn’t run properly.
23. What is the difference between the include() and require() functions?
24. How do you fix error types? Give specific examples.  
25. What method do you follow to generate random numbers in PHP? 
26. Walk me through how to get details for a browser using PHP.
27. What’s the process to set cookies for a website? 
28. Explain SQL. How would you create a MySql database using PHP?
29. What are your primary responsibilities in the software development lifecycle?
30. How would you develop and integrate plugins for PHP frameworks? 
31. What features help increase user experience quality? Name any examples you find appropriate.
32. Write a basic web application in PHP that can create, list, edit and delete student records.
33. Write a program in PHP to check if a number is prime.
34. Write a program in PHP to check if a sequence is a Palindrome.
35. Write a one-liner that will count the number of capital letters in a file. Your code should work even if the file is too big to fit in memory.

PHP Developer Interview Questions and Answers

Every interview is different and the questions may vary. However, there are lots of general questions that get asked at every interview.

Below are some common questions you'd expect during PHP Developer interviews. Click on each question to see how to answer them.

1. What is Your Salary Expectation?
2. Why Do You Want To Leave Your Current Job?
3. Why Do You Want This Job?
4. Do You Have Any Questions for Us?
5. What is Your Greatest Strength?
6. Are You a Leader or a Follower?
7. Why Should We Hire You?
8. Tell Me About Yourself
9. What Is Your Greatest Accomplishment?
10. What is Your Greatest Weakness?