PHP Developer Interview Questions for IT Hiring

Introduction

Hiring the right PHP Developer is essential in the Information Technology industry to ensure stable, secure, and scalable web applications. A focused screening process helps identify candidates who combine solid coding skills with practical experience in real-world projects.

This guide presents role-specific PHP Developer interview questions across basic, intermediate, and advanced levels, plus five pre-screening one-way video interview questions ideal for ScreeningHive. Use these questions to standardize evaluations and speed up candidate selection.

PHP Developer Interview Questions

Basic PHP Developer Interview Questions

• What is PHP and what are its primary use cases in web development?
• Explain the difference between GET and POST requests and when to use each.
• How do include, require, include_once, and require_once differ?
• Describe PHP data types and how type juggling affects comparisons.
• How do you connect to a MySQL or MariaDB database from PHP? Outline the basic steps.
• What are sessions and cookies, and when would you use one over the other?
• Why is htmlspecialchars important and when should you use it?
• What methods and tools do you use to debug PHP code?

Intermediate PHP Developer Interview Questions

• How do you prevent SQL injection attacks in PHP applications? Describe an example using prepared statements.
• What steps do you take to handle file uploads securely and validate uploaded content?
• Describe how you would build a simple RESTful API endpoint in PHP and manage request validation.
• Explain how Composer works and how you use autoloading in your projects.
• What performance optimization techniques have you applied to PHP applications, including caching or opcode caching?
• How do you manage dependencies and version compatibility across multiple environments?
• Describe your approach to error handling and exceptions in a production PHP application.
• How do you structure code in an MVC or similar pattern for maintainability?
• How would you manage sessions in a load balanced or distributed environment?
• What is your approach to writing unit and integration tests for PHP code and which tools do you use?

Advanced PHP Developer Interview Questions

• Design a scalable PHP application architecture for a high traffic site. What components and patterns would you include?
• Explain PHP memory management and garbage collection. How can you reduce memory usage in long running scripts?
• What strategies do you use for database scaling and query optimization in complex applications?
• How would you approach splitting a monolithic PHP application into microservices? What trade offs would you consider?
• Describe the tools and process you use to profile and tune PHP application performance.
• What advanced security controls do you implement for enterprise PHP applications to mitigate XSS, CSRF, and other threats?
• How do you integrate continuous integration and continuous deployment for PHP projects and ensure safe releases?
• Describe your approach to refactoring large legacy PHP codebases and reducing technical debt.
• Which caching layers would you implement across application, database, and HTTP to improve throughput?
• How do you lead a team of PHP developers to improve code quality, enforce standards, and manage code reviews?

Pre-Screening Video Interview Questions for PHP Developer

These five one-way video interview questions are ideal for pre-screening candidates on ScreeningHive. Each prompt is crafted to evaluate technical ability, experience, communication, and problem solving while enabling consistent, asynchronous assessments.

1. Briefly describe your professional experience with PHP and the most significant project you worked on.

   This question evaluates overall experience, project exposure, and the candidate's ability to summarize technical work clearly.

2. Which PHP frameworks and libraries do you prefer and why? Provide specific examples of when you chose them.

   This question assesses familiarity with tooling, decision making, and practical framework experience.

3. Describe a performance issue you encountered in a PHP application and the steps you took to resolve it.

   This prompt checks problem solving, diagnostic methods, and understanding of optimization techniques.

4. How do you approach security when developing web applications in PHP? Give concrete practices you follow.

   This question evaluates awareness of secure coding, input validation, and common web vulnerabilities.

5. Explain how you ensure code quality and maintainability, including testing, documentation, and reviews.

   This item reviews the candidate's process for testing, collaboration, and sustaining long term code health.

Conclusion

These PHP Developer interview questions help hiring managers, recruiters, and HR teams evaluate candidates across core skills, practical problem solving, and architecture-level thinking. Using a structured set of questions improves hiring consistency and reduces time to hire.

ScreeningHive's one-way video interviews provide a faster screening workflow and standardized evaluations so teams can shortlist the best PHP Developer candidates more efficiently. Incorporate these pre-screening interview questions for reliable, repeatable assessments.