PHP Job Interview: What to Expect and How to Prepare

Published on July 14, 2026 • 10 min read

Most PHP interviews don't just test whether you've memorized syntax — they test whether you can reason through a problem out loud. That distinction changes how you should actually prepare. Here's what a typical PHP interview looks like, the questions that come up again and again, and a preparation plan built around demonstrating ability, not reciting definitions.

How PHP Interviews Are Usually Structured

Structure varies by company size, but most PHP interview processes for junior-to-mid roles follow a similar shape:

• Screening call. A recruiter or hiring manager checks basic fit — your background, why you're interested, salary expectations.
• Technical screen. Often a live coding exercise or take-home assignment — building a small feature, fixing a bug, or writing a function under mild time pressure.
• Conceptual/whiteboard round. Questions about PHP fundamentals, OOP, databases, and how you'd approach a design problem — less about producing perfect code, more about how you think.
• Team/culture fit round. Less technical, more about communication and how you work with others.

Internships and junior roles often compress this into 1-2 rounds rather than 4 — but the technical screen almost always survives, even at the entry level.

Common PHP Interview Questions

These come up often enough that they're worth being genuinely comfortable with, not just able to define:

• What's the difference between == and ===, and why does it matter?
• Explain the difference between include, require, include_once, and require_once.
• How do sessions differ from cookies, and when would you use each?
• What is a PHP array under the hood, and how is it different from arrays in languages like C or Java?
• Explain the four pillars of OOP (encapsulation, inheritance, polymorphism, abstraction) with a PHP-specific example.
• What's the difference between abstract classes and interfaces in PHP, and when do you reach for each?
• How would you prevent SQL injection in a query, and why does string concatenation put you at risk?
• What is Composer, and what problem does it solve?
• Explain how PHP handles memory and garbage collection at a basic level.
• Walk through how you'd design a simple REST API endpoint in PHP.

Notice the shape of these questions: almost none of them are "define X." They're "explain X and when you'd use it," or "walk through how you'd build Y." That's intentional — interviewers are checking whether you understand the reasoning, not whether you've memorized a glossary.

The Live Coding Round

This is where preparation actually gets tested. Typical exercises include: filtering or transforming an array of data, writing a function to validate input, building a small CRUD-style feature, or debugging a snippet with an intentional bug planted in it.

The single biggest differentiator here isn't knowing the "trick" to the exercise — it's whether you can talk through your thinking while you code, handle a mistake calmly, and ask clarifying questions instead of guessing at requirements. Interviewers routinely say they'd rather see a candidate get partway there while reasoning clearly than produce a perfect answer silently.

How to Actually Prepare

Re-reading a list of interview questions the night before rarely helps — recognizing an answer isn't the same as being able to produce one under pressure. A more effective prep sequence:

1. Explain each concept out loud, from memory, with no notes. If you can't, you don't know it yet — you've recognized it.
2. Practice small coding problems under a timer. Array manipulation, string parsing, and basic logic problems, solved without reference material, build the exact muscle a live coding round tests.
3. Narrate your thinking while you solve problems, even alone. Talking through your reasoning is a skill on its own — it feels awkward at first and gets natural with repetition.
4. Review your own past projects. Be ready to explain a real decision you made — why you structured something a certain way, what you'd do differently now.
5. Prepare 2-3 questions to ask them. About the codebase, the team's use of frameworks, or how they handle legacy code — it signals genuine engagement, not just job-hunting on autopilot.

If step 2 feels like the hard part, that's usually a sign of tutorial hell rather than a lack of talent — it means you've seen a lot of PHP but haven't produced much of it under your own steam yet, and that's very fixable with deliberate, timed practice rather than more passive review.

Practicing structured problems under light time pressure, without reference material, is exactly what a good problem-based workbook trains — more on that below.