15 Software Developer Interview Questions and Answers

Interviews can be intimidating, but they’re also exciting (yes, really!). First, they give you a chance to wow your interviewer with your programming knowledge and expertise. Second, they also allow you to peek behind the curtains of the companies you’re applying to and see whether you actually want to work there. (That’s why it’s essential to have a list of questions to ask your interviewer, but more on that later.)

Still, you’ll want to prepare before you walk into your interview. Reviewing some common interview questions beforehand will help put your mind at ease so that you can deliver your answers more confidently when the day comes.

So, to help you prepare, let’s take a look at some of the most common Software Developer interview questions and their answers.

Entry-level Software Developer behavioral questions

As an entry-level Software Developer, you can expect some behavioral questions that will help the interviewer understand who you are as a person.

1. What projects are you currently working on?

Since you’re applying for an entry-level job, the projects you list can be side projects. The interviewer wants to know that you’re actively coding, along with what type of technologies you use, and if you’re passionate about the work.

2. Why should we hire you for this position?

To answer this question, you’ll want to know about the company you’re applying to. You don’t want to be overconfident and respond with a generic answer like, “Because I’m smart, motivated, and want this job.” Instead, use your knowledge of the company to highlight how you can contribute to their goals.

3. Where do you see yourself in five years?

This question helps the interviewer determine if you’ll stick around for a while and if your goals match what the company can provide. Answer this question as honestly as possible.

First, you need to know what your long-term goals are. Then, find a connection between those goals and the job description. If the company has different levels of Software Developers, you might say that you want to work toward a mid or senior-level position.

Entry-level Software Developer technical questions

These types of questions will test your understanding of basic software development principles.

4. What is an abstract class, and why would you use it?

An abstract class is a class that contains abstract methods. These methods have declarations but no implementations. Instead, they’re implemented by sub-classes of the abstract class, which makes them more flexible and easier to customize.

5. Explain inheritance

Inheritance is when an object or class is based on another object or class and uses the same implementation. For example, you could have both a Car and a Motorcycle class that inherits from a Vehicle class.

6. What’s the difference between method overriding vs. overloading?

These are both examples of polymorphism. Method overloading is when you have the same method but change its signature, parameters, or return type. Method overriding is when you have a method that belongs to an extended class, and you change its behavior.

Senior-level Software Developer behavioral questions

Senior Software Developer candidates will likely face more complex questions during their interviews. These questions help the interviewer see if you’ve learned from your experiences and added value to companies you’ve worked for in the past.

7. What’s your biggest professional success so far?

Listing your professional accomplishments before your interview will help you prepare for this question. It helps if you choose those that involved working with a team or adding value to an enterprise.

8. Tell me about a time in your professional career that you failed

This question can be hard to answer if you aren’t prepared for it, so make a list of your failures before the interview and go through them. The interviewer wants to know that you can acknowledge your weaknesses and take responsibility for your failures.

Still, this question also gives you the chance to show that you know how to make the most of a bad situation. After explaining the problem, follow up with a description of how you resolved it to illustrate your problem-solving ability.

9. Have you ever identified a potential business problem and proactively implemented a solution?

This question is a test of your ability to handle and resolve unexpected work situations. Companies want a Senior Software Developer who can develop solutions without always relying on guidance.

Senior-level Software Developer technical questions

Senior Software Developer technical questions are usually more in-depth than those asked of junior developers and may include more algorithm and systems questions.

10. What are the differences between functional and object-oriented programming?

Your answer to this question shows your knowledge of the two main software development paradigms. Here are the differences between the two:

Functional programming relies on immutable objects and avoids mutating states. Object-oriented programming depends on state mutation and the in-place modification of objects.
The main concept in functional programming is the function. In object-oriented programming, it’s the class.

11. What sort would you use if you required tight max time bounds and wanted highly regular performance?

I would use a Balanced Tree Sort because it’s guaranteed to have an O(n log n) runtime.

12. How would you scale access to a system like Twitter?

There’s no exact answer to a question like this. The interviewer just wants to determine if you have systems design knowledge. Most of the time, questions like this are vague, and the interviewer expects you to ask for requirements to narrow down your answer.

Depending on those requirements, your answer could be something like this:

“I would maintain a cache for each users’ feed. Then use an asynchronous queue service to handle message consumption to update the feed cache and call push services. Because each push job is stateless, it’s linearly scalable by adding more workers to consume the queue.”

Questions to ask during a Software Developer interview

You should also ask your own questions during the interview to show the interviewer that you’re truly interested in the company. Here are some questions to consider asking during your Software Developer interview:

13. Why do you enjoy working here?

This question helps you determine if you’ll be a good fit for the company. It’ll also give you a sense of the organization’s structure and the personality of your future manager. If their answer doesn’t align with the type of work you enjoy, then maybe the job isn’t right for you.

14. What are the biggest challenges facing the team right now?

Asking this question demonstrates that you care about the direction the company is taking and your motivation to contribute to organizational goals.

15. Is there room for growth?

If you ask this question, it shows the interviewer that you’ll be a motivated employee who wants to move up the ladder and develop new skills. It also shows you plan to stay with the company long-term.

Preparing for a Software Developer interview

By reviewing Software Developer interview questions, you’ll be more relaxed in your next interview and confident that you can answer any questions that come up with ease. Using the questions above is a good way to get started.

For technical Software Developer interviews based on a specific programming language, you may want to check out the following courses:

To learn more about the interview process itself, check out our article on the differences between behavioral and technical interviews, as well as our complete guide on how to ace a technical interview. And for the ultimate interview prep, you can take a course from the interview prep section of our course catalog.