Technical Interview Questions to Hire PHP Web Developers
Here are some technical interview questions categorized by different skill sets to help you assess potential PHP web developers.
Core PHP Knowledge
Dive into the heart of PHP knowledge to unveil the candidate's grasp of essential concepts by asking the following questions:
- Explain the difference between static and dynamic typing in PHP.
- Describe the different types of data structures in PHP (arrays, objects, etc.).
- How do you manage errors and exceptions within your code?
- Explain the superglobals in PHP and their uses.
- What are the security implications of adding user input to your code?
Make sure that candidates comprehend core concepts, can eloquently articulate and apply them. If you’re looking for full-stack PHP/JavaScript Developers, extend the list of tech interview questions to check the skills needed for both back- and front-end development.
Object-Oriented Programming (OOP)
Ascertain the candidate's prowess in applying Object-Oriented Programming principles to PHP:
- Explain the concept of inheritance, polymorphism, and encapsulation in OOP.
- When would you use a class vs. a function in PHP?
- Describe how you implement access modifiers (public, private, protected).
- How do you handle dependency injection in your code?
Hire PHP website developer whose understanding of OOP extends beyond theory into practical PHP application. To check this, you can ask candidates to provide their Git portfolios which demonstrate previous experience applying OOP.
Frameworks and Libraries
Probe into the candidate's familiarity with PHP frameworks and libraries that shape modern development:
- What PHP frameworks have you used? Which ones do you prefer and why?
- Describe the benefits of using a framework vs. writing custom code.
- How do you choose the right framework for a project?
- Explain your experience with specific libraries you've used (e.g., PHPUnit, Composer).
Assess developers’ ability to align the right frameworks and tools with the unique demands of each project.
Database Interaction
Check the candidate's proficiency in orchestrating effective interactions between PHP and databases.
- Explain the difference between PDO and MySQL for database connection.
- Describe how you perform CRUD operations (Create, Read, Update, Delete) on a database.
- How do you prevent SQL injection vulnerabilities in your code?
- Have you used any ORM (Object-Relational Mapping) tools?
Hire PHP web developer proficient in synthesizing database operations seamlessly while adhering to stringent security protocols.
Testing and Debugging
Last but not least, assess the candidate's proficiency with testing and debugging tools within the PHP landscape:
- Explain the importance of unit testing in PHP development.
- Describe different types of unit testing frameworks.
- What tools and techniques do you use for debugging?
Hire PHP web app developers committed not just to coding but to generating clean, testable code, with a keen eye for troubleshooting.
While these questions can serve as a basis for tech interviews, make sure to tweak this list depending on the specific experience levels you seek in your PHP team member.