4 Common Back-End Developer Interview Questions

The best website back-ends function so well that the work can go unnoticed. Going unnoticed for back-end developers looking to get hired at a full-time job is the exact opposite of what they want. 

You may have a portfolio filled with great website projects you’ve completed. These examples of your work may have excellent navigability, speed, and functionality. However, it's also crucial to be prepared to answer difficult questions during your interview to secure your desired job.

Even though each company is unique, there are common questions that many human resource managers and C-suite executives use when looking for someone to fill their need for a back-end developer. They present challenging questions to determine strengths and weaknesses—and decide if you’re right for the team.

To feel more comfortable and confident, consider your answers to the following questions in advance. If you can calmly and friendlyly point to specific areas in your work history or portfolio that prove your capabilities, you can set yourself apart from the competition.

Expert advice

"Getting good at coding interviews takes time," says Mari Batilando, a Meta Software engineer with eight years of experience. "Make coding exercises a habit. Learn how to love problems you don't know how to solve. Be genuinely curious, and don't be afraid to fail. If you're not failing, then you're not trying hard enough."

1. How did you first get involved in computer science?

Why do interviewers ask this question?

This is often the ice-breaker question, designed to give you an overview of your early years, training, and, importantly, the motivation that drives you in this career.

Example answer

“When I was a child, I always loved technology. I would spend hours looking at programming code, and I was even able to teach myself some basics. As I got older, I became interested in how mobile app development worked. That’s when I decided to focus my studies on back-end development and majored in computer science. I love the idea of creating a framework structure that makes all the pretty designs and features operate exactly as the team envisioned. I feel like I help bring dreams to life.”

2. What has been your role in development projects in the past?

Why do interviewers ask this question?

This type of question hits on a few important points that interviewers care about. First, they typically want specifics concerning the kind of work you can do. If you’ve worked in a particular programming language or model, bring it up in your answer.

Second, this question is about how you interact in a team environment. Although coding can often be done in nothing more than a quiet corner, a back-end developer must frequently work directly with digital designers and managers who may require help in finding solutions. Remember to highlight times when you managed other team members or had to compromise to create an end product that everyone loved.

Example answer

“Let me show you one of the projects I’ve brought as part of my digital portfolio. Here, I built out the back end of the site using Ruby, although normally, I am more comfortable working in JavaScript. The digital designer and I agreed on the functionality of this interesting feature, which allowed for a search of tourist activities from a constantly expanding list of recommendations by the company. Based on that plan, I was able to oversee the work of two other developers, and together we built out the framework in just a matter of weeks. It was an exciting project.”

3. Can you identify limitations within the development languages you prefer?

Why do interviewers ask this question?

This question may start a series of detailed questions to extract the technical skills and knowledge required for the role. While in the interview seat, the best course of action for you is to ensure that whatever you discuss—anything from stack overflow to loose coupling to domain logic—is completely understandable to the person asking the question.

They want to make sure you’re well-trained, so show them you can speak the language of technology in a way that also demonstrates humility and a willingness to listen to others. If you don’t know the answer, take a breath. It’s better to say that you don’t know but would like an opportunity to research and find out rather than stammer with the first thing that comes to mind.

Example answer

“I love working in Python, which is powerful enough to support two of my favourite apps, Spotify and Instagram. It’s open-source with asynchronous coding, and I appreciate my ability to integrate AI into the back end. However, there is plenty to critique. It’s slow, and it’s not the best for mobile app development. It also uses a lot of RAM.”

4. Where do you see yourself professionally in five years?

Why do interviewers ask this question?

This question is so common in interviews that it’s almost not worth including—except it frequently trips up back-end developers. Managers want to know they are hiring a forward-thinker with long-range goals. Especially in technology-based careers, the work you’re doing is constantly evolving. Show the interviewer that you plan to stay up to date. That way, the company can be, too.

Although being a professional means setting personal matters aside, this question also allows you to share something about yourself they may not know.

Example answer

“Five years from now? I think about that a lot since I’ve recently proposed to my long-term partner and hope to have a family someday. I am very interested in having the stability of a solid career with this company, which I admire for its domination of the industry. Beyond that, I want to keep learning. I fully intend to continue my education through online courses and certification programs so that I can be a better team player wherever I work. The best thing about this type of work is that so much will change in the next five years; I can’t wait to see.”

General interview tips

Landing a job takes more than a strong resume and interview responses, even in the above examples. Be sure to consider the following when planning for the big day:

1. Research the company.

You should know as much as possible about the company, including its online presence, back-end structure, goals, and team. If possible, follow them on social media and be current on any news that may impact the business’s overall success. An interview is an excellent time to ask informed questions, not basics.

2. Come prepared.

You should look tidy and dress professionally, even if the company is famous for its casual brand. Also, bring a flash drive or other type of storage, your laptop, and ready-to-launch links to your portfolio of professional work. Include a list of references your interviewers can follow up with afterward.

3. Ask questions.

Interviews aren’t just for your potential manager to decide if they like you. These meetings are also opportunities to determine if you fit into the company culture and can be an asset to the projects they assign you. Make sure the day-to-day responsibilities and expectations are clear. Ask about performance metrics. See if they pay for additional education.

4. Follow up with an email.

When you finish the interview, give a firm handshake to each person in the room and look them in the eyes. Make sure they know you’re grateful for their time and consideration, whether or not you are the person for the job. Get each of their names and contact information, and that evening, follow up with an email to all interviewers. Answer any lingering questions from the interview, and again, thank them sincerely.

How certifications and certificates can help 

Sometimes, managers and human resources professionals are more trained and experienced in hiring psychology than in the details of back-end development. After all, that’s why they are considering hiring you. You can easily show your skills in a way they’re sure to understand by providing credentials you’ve earned over the years.

Certifications and certificates show that you’re interested in staying current with the latest technologies and processes constantly evolving in your line of work. Just getting started? Consider completing the Web Applications for Everybody Specialization from the University of Michigan to validate your proficiency in PHP, MySQL, jQuery, and Handlebars, or completing the Meta Back-End Professional Certificate.