August 25, 2021

PHP Developer Interview Questions and Effective Hiring Tips

What you should know about PHP? Indeed, you as a business owner, have the right to know nothing about this programming language, in contrast to a PHP developer you intend to hire. They, in turn, are better to know as much as possible to make your project technically powerful, and your task is to verify the skills and competencies highlighted in their CV are actually strong. Asking PHP developer interview questions is one of the ways to do it.

PHP Development Interview Questions You Should Ask
Advanced PHP Interview Questions
How to Hire a PHP Developer Effectively
Conclusion

Hire our professional PHP developers

PHP Development Interview Questions You Should Ask

There are three types of interview questions for experienced PHP developers. You should ask them all to make sure the candidate has enough technical expertise to create your project, there is enough evidence to rest assured their qualifications are backed up by their real experience, plus there is a cultural and value match. Evaluating your PHP developers from three different angles will help you make the right choice and avoid overspending on the hiring process.

Below are the interview questions for experienced PHP developers you should ask.

1. Technical interview questions for PHP developers

The first task is to evaluate the technical background and make sure the candidate understands the technology. Ask up to ten questions - these are enough to verify the candidate either has strong knowledge or there are some gaps. When preparing the list of questions, keep in mind that the junior PHP developer interview questions are pretty different from the ones you can ask a Senior programmer.

Below are some sample ideas for the simplest to advanced PHP interview questions:

What is PHP?
What apps can you create with this programming language?
Is PHP used on the front or backend?
What are PHP scripts?
What is an array in PHP?
Are multiple inheritances supported in PHP?
How to handle exceptions in PHP?
How objects are passed in PHP?
Why is PHP called a hypertext preprocessor?

2. Experience and skills PHP backend developer interview questions

At the next stage, ask full-stack PHP developer interview questions that are directly related to the candidate’s journey in the world of PHP. Here is what you can ask.

Ask about their previous experience. Ask a candidate about their previous workplace but don’t leave the programming language context. For example, you can ask the candidate to briefly describe their learning and career path by briefly describing the companies and industries they have worked for.
Finished projects and their challenges. Then, proceed with the details. Ask the candidate to tell you about the most prominent PHP projects they handled, and pay special attention to the challenges they faced. Ask to tell more about the ways to avoid PHP pitfalls in different use cases.
Hard and soft skills evaluative-questions. After asking the previous two questions, you are likely to get the first impression of both hard and soft skills of the candidate since interview storytelling is impossible without mentioning them, showing the attitude to the previous team and employee. Still, make sure to ask additional questions that may be essential for the candidate to become a part of your team.
CV and portfolio review. Align the portfolio and CV with stories and case studies the candidate has shared in response to the previous questions, and ask additional questions if you feel like any of the projects mentioned in their CV can be the source of insights for your own one.
GitHub profile review. As the last step, review the candidate’s GitHub profile or ask the third-party tech specialists to help you if you have no PHP coding skills.

3. Value-based full-stack PHP developer interview questions

On the final step of your interview, ask some questions about the candidate's values and expectations to make sure the candidate fits the project as a person and there is no expectation vs reality mismatch. Here are some ideas:

Describe your perfect team collaboration specifics.
What is the biggest problem of modern web projects?
How can your Project Manager or Team Lead support your best?
What values do you appreciate most in your future employee?
What are the kinds of projects you will never work on?
What was your biggest career mistake?
What traits do you value in your colleagues?

This list of PHP developer interview questions can go on and on. Make sure to shortlist the most essential value-based questions aligned with your project specifics and ask them first

4. Behavioral questions to ask your future PHP developers

In addition to value-based and PHP advanced interview questions, you are also welcome to ask some behavioral questions. These are the questions that allow you to get an idea of how a person has behaved or is going to behave in a specific situation.

When asking these questions, be guided by the specifics of your project. For example, well-predictable solutions that will be developed by the Waterfall methodology by a small team are likely to promise less stressful situations and technical challenges. And vice versa, technically complex projects with the possibility of changing the development strategy require more advanced communication skills, stress resistance, and a lot of practical experience in solving the issues.

Below are some PHP interview questions for experienced developers you can ask to evaluate the specifics of their behavior during the project creation:

What was the biggest risk you have ever taken during your career?
Was it your responsibility to take it?
What was the outcome of the situation and how did you resolve it?
Will you take the responsibility for the tasks you don’t know how to handle? What will you do next?
Have you ever faced burnout? How did you cope with it?

And now let’s look at some of the questions you might ask a PHP specialist with 1 year experience versus the one with 3 years’ experience

PHP Interview Questions for 1 year experience vs for 3 years’ Experience

Interview questions in PHP can vary a lot. So, how do you choose from the abundance of questions and set up the most appropriate interview questions on PHP? It mostly depends on whether you are looking for PHP freshers or slightly more experienced specialists. Nevertheless, we would still recommend to start from PHP basic interview questions like

What is the definition of PHP?
What are the common uses of PHP?
What are the features of PHP variables?
Name the types of PHP variables

After asking these basic php interview questions, you can move further with additional questions for PHP freshers or more experienced PHP specialists.

PHP Interview Questions for 1 year Experience

If you are looking for a PHP developer with 1 year experience, you might ask the following interview questions in PHP:

What is the difference between variables and constants in PHP?
Can you explain what a session in PHP is?
What does PEAR stand for?
What are the advantages and disadvantages in PHP?

Then you can continue with the following more specific PHP interview programming questions

Does JavaScript interact with PHP?
How to create cookies in PHP?
Can you name major differences between ASP.NET and PHP?
What is ‘escaping to PHP’?
What is the major difference between the include and require functions?

PHP interview questions and answers for freshers may vary depending also on the type of project you are working on, the number of team members working on the project, whether or not you have a supervisor willing to help freshers solve some problems if any. During the interview process, you might also take into account the interviewee’s willingness to fill in some knowledge gaps (if that’s the case) and grow professionally.

PHP Interview Questions for 3 Years’ Experience

You can include the following PHP programming interview questions for more experiences specialists:

What is Memcache and Memcached in PHP?
How do you connect to a URL in PHP?
How do you compare objects in PHP?
How do you create an API?
Name three types of arrays in PHP
What is the difference between GET and POST?
What is the difference between “echo” and “print”?

You can also come up with such an interview question for PHP that would require the interviewee to give a practical example. For instance, you could ask to explain the syntax for ‘foreach’ loop with the example.

Try to prepare some of the questions beforehand, and some of them you could ask on the spot. Sometimes it’s enough to ask a few questions, sometimes you need to ask more questions to check on the candidate’s knowledge.

In case you need to hire a highly-skilled senior PHP developer with about 5 years of experience, you should come up with more advanced PHP coding interview questions.

Advanced PHP Interview Questions

If your project requires hiring the top-skilled developers of the Senior level, you have to include the PHP interview questions for 5 year experience in the list of the ones to ask. In this case, you are better to hire a technical consultant who can help you with choosing the right interview questions and validate the correctness of the answers. Below are some of the basic PHP interview questions for experienced candidates:

How can you pass a variable by reference?
What is the main difference between require() and include()?
What does $GLOBALS mean?
What is the use of ini_set()?
What are the different MySQL database engines?
What is the difference between MyISAM and InnoDB?
How to make a database connection in PHP?
Declare a function with default parameter
What is the use of the .htaccess file in PHP?
How to download files from an external server with code in PHP?
How to handle exceptions in PHP?
What are the different PHP errors?
How many types of errors are there in PHP?
How can you enable error reporting in PHP?
What is the difference between session and cookies in PHP?
What are the main differences between const vs define
What is the difference between file_get_contents() and file_put_contents() in PHP?
What is stdClass in PHP?

Such a list of technically complex questions may seem overwhelming. That’s why we, at IT Master Soft, validate the experience and expertise of our developers in advance so that you can better focus on your project specifics rather than getting lost in technical details. In the next section, we are going to overview the questions that will help you make sure of an actually perfect fit.

Is there an easier way to hire PHP developers?

How to Hire a PHP Developer Effectively

Interviewing your PHP developers can take some time and effort. Here is how you can make the process of hiring and interviewing even more effective.

Be specific

PHP has a lot of use cases. With the help of this programming language, you can build dynamic content apps, social platforms, chatbots, and much more. That’s why it is always better to consider the candidates with experience in the specific use-case, which, logically, matches or at least coincides with your project specifics. Try to prepare specific php questions for interview to make sure you’ll find the best match for your project.

Offer the opportunities instead of just salary

Modern IT specialists know their worth, and mostly, aren’t eager to work in exchange for the salary only. They want collaborative environments, knowledge exchange and professional growth opportunities, flexible schedules and no micromanagement, adequate corporate culture, and the values worth standing for. Make sure to offer something beyond the salary only to make your company attractive for the top talents.

Make sure there is a cultural match

Some companies intentionally staff their development teams with specialists from different countries, since teams will thus have different mentalities, mindsets, and cultures. This is called cultural diversity, and some experts agree that it actually helps with solving the problems better and suggesting non-standard solutions as different people have different problem-solving approaches. Still, it is important to find the balance between cultural diversity and cultural match, making sure your future PHP developers understand your project values, the values of its future users, and most importantly, sincerely share them.

Consider a ready-made team we already have

Hiring technical specialists is challenging, especially if you don't have enough engineering background to correctly evaluate a candidate's skills and competencies, and match them with your project. What’s more, the process of hiring on your own can cost a lot. On average, filling the position with the help of a recruiting agency costs 50-100% of the salary of the candidate hired. Additionally, you have to pay onboarding and training costs, plus retain your employees since replacing them costs even more than hiring from scratch. Considering all these expenses for hiring a PHP developer in-house, outsourcing your PHP development is a wiser option. We, at IT Master Soft, already have a PHP development team that will be able to get down to your project almost instantly.

Get in touch with a reliable team staffing vendor

As one more effective option for making your in-house PHP development team stronger, consider extending it with third-party developers. This is a top strategy for the development team scaling since it also allows you to avoid hiring overspending and time waste while making your remote team flexible, effective, and easily controllable.

Let’s scale your PHP development team together. We are here to strengthen your in-house programmers with our remote PHP specialists right now!

Conclusion

When hiring a PHP developer, you have to make sure that the candidate not only has all the necessary knowledge and skills but there is also a cultural and value alignment. Also, make sure you go through php basics interview questions as well as php coding interview questions before choosing the right candidate for your project.

All these points are equally important when outsourcing your software development and extending your tech team. A-Team Global is ready to help you with any of these tasks, perfectly matching our programmers with your project needs and the development strategy with your business goals.