Software Engineer Interview Questions

Basic requirements for software engineering interview questions

Software engineers are critical for any and all types of organizations, which is why it is very important to carefully pick and choose the best people for your software development projects.

Interviews are a great vehicle to screen candidates and find the right fit for your team. As much as you follow a standardized interviewing process and list of questions, no two interviews are ever exactly the same. To help you weed out mediocre candidates from extraordinary applicants, in this article we cover the details of having a well-prepared set of software engineer interview questions.

Not only is the interviewing process vital to obtaining a high-level understanding of what each candidate brings to the table, but it is also an opportunity to clearly define job roles and identify business and technical needs of the project and/or organization. With that said, however, it is also important to keep in mind that job scopes are dynamic and are subject to change based on the necessities of a particular project.

To get started, we identify some of the basic areas that are essential in the grand scheme of software engineering interview questions, and we discuss them in the following section:

Technical background
- Software Development Lifecycle knowledge
- Models and methodologies
- Software tools and technologies
- Programming languages
Soft skills
- Communication
- Teamwork
- Critical thinking
- Leadership
- Polite and positive attitude
Types of projects the candidate has worked on
Expertise in similar projects and circumstances

Defining requirements for the project

As we mentioned earlier, it is vital during the interviewing process to have a clearly defined overview of what the software development project entails and what is required of the successful candidate. This includes defining the requirements for the project, both business and technical.

As you define the requirements of the project, you’ll know exactly what to look for and request from a candidate. Whether it’s a specific technology, method, tool, or approach, you can interview applicants who specialize in your identified area.

For example, if your project requires an Agile iterative approach and you are looking for a Scrum Master to lead the entire project’s lifecycle, it’s only sensible to request that job applicants are certified as Scrum Masters or have an appropriate foundation based on Agile and Scrum.

Finding key qualifications on a software engineer interview

While the number of interview phases may vary, there are at least three basic phases for an effective interview: (1) getting to know the candidate, their experience, and previous projects they’ve worked on, (2) a more in-depth look into their technical knowledge and skills to determine if they are the right fit for the unique role, and (3) clarify any questions the applicant may have about the position.

Finding key qualifications across these phases of a software engineer interview is crucial to selecting the right talent. As some say, everyone wants to find the software engineer “unicorn” - an extraordinary and seemingly elusive candidate who checks off every item on the hiring team’s checklist in terms of technical background, knowledge, soft skills, experience, budget, etc.

Through a series of well-defined software engineering interview questions and phases, it is easier to discover the key qualifications of applicants. It’s important to craft questions that not only focus on broad engineering skills but on specific attributes that are necessary for the particular position. This will help pinpoint crucial qualifications that will be a strong fit for the role.

For example, if the seniority level of the role for a Project Management position is considered junior, you may want to design software engineering interview questions that focus on soft skills such as communication, critical thinking, ability to meet deadlines, and more. Since the role doesn’t necessarily require a senior level of foundation in Project Management principles and certifications, you can focus on identifying candidates who fit the bill in terms of attitude and eagerness to learn and adapt to your business environment.

On the other end of the spectrum, if the role requires a higher emphasis on technical skills such as a DevOps engineer or a QA team lead, you must concentrate on designing interview questions that tackle technical aspects of the role in terms of tools, technologies, methodologies, and more.

Remember, technical skills are a must-have to look for in software engineering interview questions, but in some positions, it is just as crucial to look for specific soft skills, such as communication. In essence, it all depends on the role.

Let’s review some general questions that may be encountered in software engineer interviews.

General questions on an interview

In this section, we present a condensed guide to general questions and topics included during a software engineering interview.

Discussion of previous projects

The topic of experience is always relevant and crucial in interviews. Regardless of whether candidates possess a wealth of experience or are just beginning their professional journey, it is essential to pinpoint a candidate’s standing in terms of how much knowledge and background they bring to the role to be filled.

Discussing previous projects is a great method to learn more about an applicant’s experience. Through assertive questions about previous projects, interviewers can learn about and understand both the applicant’s technical skills and soft skills.

An applicant’s approach to handling previous projects shows how well they handle pressure, deadlines, technologies, different environments, changing requests, and more. All of these subjects tell a lengthy story of how an applicant may react and adapt to the upcoming challenges of the new position.

Some sample software engineer interview questions about previous projects include:

What has been the most challenging project you’ve worked on and how did you cope with its complexity?
What has been the most rewarding project you’ve worked on and what do you think were the factors that made it successful?
What methodologies have you used in past projects?
What tools and technologies have you used in past projects?
What is the latest project you’ve worked on? How did you contribute to its success?
Talk about a project where you had to make critical decisions quickly.
Based on previous projects, what is your preferred method to manage projects?

Software engineer technical interview questions

This is the true substance of a software engineering interview because, as we mentioned earlier, technical skills are a must-have. In this section, we discuss how to distinguish the really outstanding candidates with strong technical skills from the ones who are overselling their technical abilities.

It is common to provide applicants challenges or exercises to have them execute a test or sample project to verify they are truly knowledgeable in the required technical field.

These are some common software engineer interview questions to include as part of the technical skills examination:

What is your experience in Agile software development processes?
What are your preferred programming languages?
Describe the process you use to write code, from requirements to delivery.
In which software tools are you proficient?
Which tools and technologies are you most familiar with?
Are you familiar with object-oriented programming?
Explain what an API is to non-technical folk.
What are the key elements you focus on when reviewing a peer’s code?
What is your experience with different frameworks?
What type of architecture structures have you worked with? Microservices or monolith?
What was the last new tool you used in a project? How did you adapt to integrate it into the project?

Soft skills check

Different roles, some more than others, require a higher emphasis on soft skills. There are certain roles where team communication is intensive, such as team leads, principal engineers, project managers, etc. In these roles, communication and constant team rapport are crucial for the success of the project.

Here we exemplify a few illustrative questions that help validate soft skills in a candidate:

How do you communicate effectively with the client and with other teammates?
What are your strategies to ensure a transparent communication flow during production?
During trying times, how do you contribute to uplifting the team’s spirit?
What differentiates an extraordinary software engineer from a good one?
How do you encourage teammates to collaborate?
What is your thought process to make assertive and quick-paced decisions?
How do you handle positive feedback? How do you handle negative feedback?
How do you handle delivering bad news to the client?
How do you integrate with teammates from other regions?
Are you good at expressing your thoughts without harming other people?
What is the best approach to describing your needs in a project?
How do you help your teammates reach their goals?

Applicants can be brilliant technicians or software engineers, but if they don’t possess the necessary soft skills to handle the complexities of the software project, it will be pointless to move forward regardless of how knowledgeable they might be in the technical aspect of the role.

How to narrow specialization of the software engineer

Software engineers come in many different types. While some specialize in a particular technology, others focus on mastering a specific programming language. Whether you are looking for a distinct role or a more comprehensive job description, it is helpful to know the areas in which the candidate excels.

Next, we present a few questions to narrow down the specialization area of software engineers during the interview process:

What is a typical day like in your current role?
What are you passionate about software engineering?
How comfortable are you in a startup environment? Do you prefer more established companies?
Are you keen on any particular tools or technologies? If so, do you have any certifications that validate your level of involvement?
What is your English* level? (*If the role is geared to work with English-speaking clients).

Which questions should be avoided?

Overall and across all industries, there are certain questions that should be avoided such as those related to the topics of age, race or ethnicity, religion, gender, and disability.

These topics are off limits and it is the candidate’s prerogative to share or not share such details. More than avoiding specific questions, interviewers should be watchful of certain answers that signify red flags. For example, some candidates tend to place a lot of weight on seniority, which is why they might be offended by simple questions.

These sorts of responses are off-putting and demonstrate a negative attitude from the applicant. Other red flags include the rejection of feedback, incompetence, overselling of skills, short answers, and failure to provide details of previous projects, to name a few.

How to finish the interview

Once the general questions of the software engineer interview are out of the way, you can hone in on specifics about a particular technology stack or programming language to continue to learn more about the candidate’s knowledge and approach in the subject.

As the hiring committee begins to wrap up the interview, it’s important to leave enough time for a small number of questions from the candidate. This helps build a trust relationship where candidates can ask about a team’s workload, the type of project, budget, deadline, company background, and more. It also speaks volumes about how interested the candidate is about the role, company, and project.

Overall, it’s important to wrap up interviews on a happy note and to let the candidate know about any next steps throughout the hiring process - whether it is a follow-up interview, a face-to-face meeting, a call from a hiring manager, or terminating the process. It is always appreciated when the interviewers are transparent.

We consider it crucial to finish an interview having an opinion about the candidate and their possible future within the team, project, and company. Whether the candidate is a strong hire, hire, no-hire, or strong no-hire, you should be sure of it by the end of the interview so that you make the necessary arrangements and address any follow-up steps, as necessary.

Remember that interviews can be stressful and are only one facet of the candidate’s profile, which is why it is important to ask as many questions as necessary to fully understand which candidates should move forward and appear to be a right fit for the team.