Software Engineer Interview Questions, Answers & Tips

The software developers you interview should be able to give an example of a project in which they had the most ownership or had the greatest sense of achievement, efficiency, or effectiveness from the toolchain used. They should ideally start by describing the project’s goal and briefly go through their responsibilities regarding the toolchain decision-making process.

Within Agile work practices, it’s usually a team effort to decide the best programming languages, tools, or services that fit the project best, within customer requirements. So, look for a clear explanation of your candidate’s consultation process with the customer and their teams to arrive at the best solutions.

Here are some things your candidates should cover when you ask them about past projects:

• Clearly outline the situation - what happened, what their goals were, what challenges they faced, and why.
• Concisely share the toolchain and other technologies and tools they used to solve the problem, as applicable.
• Explain the options they referred to during research, the metrics they adopted to measure the project’s success, and the pros and cons of the tech they employed.

How would you design this system for scale?

This tech interview question was designed to test a software developer’s big-picture thinking abilities.

First, your candidate should know their expected traffic level: is it 1,000, 100,000, or 10 million users per second? Based on this information, your candidate should consider data expectations for each system user, database connections (blocking or nonblocking actions), downtime specifics, and cloud considerations (if any).

They should be able to list the problems that might occur when they try to scale. Different traffic levels may be associated with different problems. Therefore, make sure your candidate has thought this through and has prioritized the problems based on traffic levels. Many codebases are not built for scale, so your candidate must explain code changes that might need to occur rather than just infrastructure expectations., This question allows you to gauge your candidate’s experience with monitoring and analyzing logs. Look for candidates who can explain their logging practices and the decision-making process behind them - especially those who focus on extracting valuable insights from logs and using them for business or customer decision-making. Your candidate should be able to share in detail an example project that they’ve monitored before. They should:

• Explain what information they logged and what questions they answered.
• Clearly explain why they decided to extract this data.
• Describe the reporting process and any associated tools they used.

Here are some additional questions that a stellar software engineer should be able to answer:

• Which logging services have you researched and used before?
• Why did you choose or look into each particular logging service?
• Was your decision due to the community’s scale, features, or size?
• In what scenarios did they check these logs? Was it scheduled daily, weekly, monthly, or as an on-demand activity?
• What information was the data transformed into? Was it used for development, business, or customer decision-making?
• Which format(s) did you use to help you make decisions?

Do you have experience in checking system performance? Any bugs/exceptions? What tools/services did you use? Why did you choose them?

Your candidates should be able to monitor system performance skillfully. Here are some questions you may want to ask your candidate:

• Whether the system is performing well is defined by the team and/or the customer requirements. List the performance criteria and the key indicators decided by the team and customer requirements and indicate how the metrics are calculated.
• The selection of tools and services depends on the team’s needs. List the features the team needs as a starting point.
• Indicate how system performance optimizations have been developed based on metrics, how they chose these optimization techniques, and the reflection in their metrics after implementation.
• List process steps you run through when facing different problems in underperforming system requirements. Indicate the goals of each of these steps. Indicate if anything should be adjusted to the processes, measurement, and reporting that could help expedite or improve the activities., For hiring managers seeking tech talent, behavioral/cultural questions are a valuable tool to assess candidates’ soft skills and determine if they are a cultural fit for the team. Ensure candidates have prepared excellent answers to these interview questions to make well-informed hiring decisions., You also want to understand the skills and knowledge your candidate has acquired over the course of their career by asking them to:
• Highlight one high-impact (preferably quantifiable) project they were involved with for each job.
• Highlight the hard and soft skills they learned from their past working experiences.
• Emphasize the initiatives they took to improve their previous company’s workflow (e.g., propose new flow to streamline sprints) or their own skillsets (e.g., engage in a hackathon with colleagues or friends).

Future expectations

Finally, you want to hear about your candidate’s aspirations and how they envision their future within your company. Ask them to:

• Describe how their existing skillsets will help them grow alongside your company.
• Convey what they hope to achieve and learn from the new job.
• Detail on products, projects, features, or initiatives they may be able to help kick off or lead in your company., * Whether they’re a proactive communicator and a good time plannerYour candidate should provide a clear outline for how they plan out their time daily and weekly. They should mention the people (i.e., product managers, designers, developers, and line managers) they actively communicate with to create a realistic day-to-day schedule. They should also highlight how often they provide project updates to relevant stakeholders.

• What their daily, weekly, and monthly work activities are Get a clear picture of what their day-to-day work looks like. They should break down the tasks they’re responsible for into different categories and indicate the percentage of time they spend working on each task category. For instance, how much time do they:

• Spend in meetings on a weekly basis
• Dedicate to routine work (i.e., debugging and maintenance)
• Spend on new product features
• Parse out for conducting work-related research

• How they strike a balance between multiple ongoing projects Ask your candidate to describe one or two instances where they had several projects running simultaneously and how they prioritized different tasks, made progress, met milestones, and worked on iterations based on feedback.

• How they deliver quality work with limited time When limited time and multiple projects are going on, they may not be able to give their 100% to their projects. Encourage your software developer candidate to expand on the following questions:

• How do you decide which tasks should be prioritized?
• How do you negotiate deadlines and milestones with stakeholders?
• How do you ensure all projects will be delivered with acceptable quality?
• At what milestones do you believe it’s ok to deliver something that’s “less than perfect”?
• How do you decide when to go back and improve the “minimum viable projects” delivered earlier in the project’s timeline?

These questions should be sufficient to help you assess your candidate’s organizational and prioritization skills. Nonetheless, depending on your candidate’s experiences, you may want to ask some other relevant questions.

Tell me about a time you failed. What is your biggest weakness?

All of us are born with certain weaknesses and have experienced failures. So encourage your candidate to answer this question candidly. Help them frame their answers better by encouraging them to choose real scenarios, highlight personal traits, and discuss conflict resolution and teamwork experience.

You can also encourage them to use the STAR method:

• Situation - The situation they were in, including the challenges they faced (i.e. technical constraints, lack of resources, crunched time, etc.)
• Task - What role and tasks they were expected to perform in the situation
• Action - What actions they took to perform what was expected of them
• Result - What happened in the end:
• How their action contributed to the failure
• What actions they took to rectify the failure

What’s the most challenging problem you have faced, and how did you solve it?

In contrast to the previous question, this question will help you understand and assess the most difficult job-related challenge your candidate faced in their career. By asking this question, you’re trying to gauge what “challenging” means to your candidate and how well they can problem-solve and handle stressful situations.

Here’s the structure and content for what a good answer would entail:

Did they choose specific examples?

• Your candidate should choose a problem they resolved effectively. They should give you some context of the problem, the process and actions they took to resolve it, and the final results.

Watch out for candidates who just end up complaining about their ex-coworkers - that’d be a red flag., This question has become a staple of almost every self-growth book or career planning blog. Some acquaintances may even ask you this question at a party. However, you don’t necessarily want the answer your candidate wrote down in their journal.

What you want to know is:

• Whether their goals align with your company’s goals
• Whether they’ll commit to your company for a while

Did they do their research?

When interviewing for a company, competitive candidates know the importance of putting themselves in their hiring manager’s shoes. To adequately answer the “5-year-plan” question, an ideal candidate will to start by researching your company.

Here are some questions a good candidate should be able to answer before they formulate their answer:

• What are your company’s mission statement and vision?
• Why is your company hiring engineers now? How do the engineering teams fit into your company’s short- and long-term goals?
• How many engineers are you hiring? Why are you hiring engineers?
• What skills or needs are not being satisfied by your company’s current engineering team, if applicable?
• (If they’re applying for a senior position) What leadership qualities is your company looking for? What were the previous managers like?
• What does your company’s product roadmap look like in the next year or two?
• What is your company’s revenue goal in the next year or two? Is the company looking to launch an IPO?

Are they able to articulate their answers?

After finding out about your company’s goals, product roadmap, and hiring strategies, they may share:

• How they plan to contribute to the company based on their position
• The training and development they hope to receive, implement, or both
• The shared values between them and your company
• Interesting projects that fit with your company’s overall goals

As the hiring manager, you’ll be gauging your candidate’s potential commitment level, so make sure to gauge how interested and committed your candidate is to your company.

• For managerial positions: They should talk about their 5-year plan for team building, tech stack updates, product roadmaps, and hiring strategies.
• For engineers: They should mention short- and long-term projects they hope to start or participate in and mention how they’d like to help the company upgrade your technical assets in a step-by-step manner., Do they know about your company’s culture, and will they be a good fit? Here are some culture-related points they should cover in their answer:
• They’re attracted to your company’s general reputation
• They’re inspired by a specific leader in your company
• They’re passionate about your company’s products and services
• They’re on board with your company’s initiatives (community engagement, public endorsements, etc.)
• They admire the company’s culture. Here are some specific examples:
• Flat organizational structure
• Transparency
• Flexibility in participating in cross-team projects
• User-centric mindset
• An encouraging environment for all employees to speak up

If they feel your company’s culture aligns well with their preferences and abilities, they should be able to clarify it in the interview.

Commitment to your company

Are they passionate about the company, and will they stay committed to it? If your candidate already displayed their commitment to your company when answering “Where do you see yourself in 5 years?” you don’t have to stress this question too much.

If you haven’t had the opportunity to evaluate their commitment to your company, the most organic way to find that out is by asking them to talk about their long-term plans in the company.

Here are some things they may talk about:

• Projects they want to start
• Potential directions they think your company can go in
• Different products or teams they want to contribute to
• Processes they’d like to participate in improving

Why should we hire you?

You want to know, as confidently as possible, that they’ll be a good hire. Every single question you ask your candidate is finally related to this overarching question: “Why should we hire you?”

Unlike the more specific questions outlined above, this generic question requires a concise but powerful answer. Think about this as your candidate’s elevator pitch - they should be able to sell themselves to you in minutes.

To develop their elevator pitch, your candidate must research, plan, and consolidate. When they’re brainstorming how to address your interview questions, they need to do their research to find out about your company’s goals, culture, and expectations for the role. Once they understand your company better, their job is to develop a solid pitch that makes the strongest argument for them.

️ Conducting the interviews

As a hiring manager, conducting software developer interviews is an opportunity to identify top talent that will elevate your team. Setting the right tone and approach can lead to fruitful conversations and help you find the perfect fit for your organization.

Setting the interview atmosphere

Creating a welcoming, relaxed atmosphere is essential for a successful software developer interview. Interviews can be nerve-wracking experiences, and candidates may not perform at their best if they feel overly stressed or uncomfortable. By setting a positive tone from the moment a candidate walks into the interview room, you can help them feel at ease and confident to showcase their skills.

One effective way you can create a welcoming environment is by beginning the interview with a warm greeting and a brief introduction of yourself (and other interviewers). Engage in small talk to build rapport and establish a connection with the candidate. For example, you can break the ice by asking them about non-work-related topics, like how their day is going and what their interests are.

Pay attention to your body language and nonverbal cues. Maintain eye contact, smile genuinely, and avoid any gestures that may come across as intimidating or disinterested. By exuding a positive and approachable demeanor, you’ll encourage your candidate to be more open and forthcoming during the interview.

Remember that a candidate who feels at ease is more likely to demonstrate their true potential and help you accurately evaluate their abilities and fit for the role.

Techniques for effective interviewing

By using effective interviewing techniques, extracting valuable information from candidates and making informed hiring decisions are crucial.

One of the most critical techniques is active listening. Avoid interrupting candidates while they respond to your questions, and give them ample time to express their thoughts fully. Listening actively shows that you respect the candidate and are interested in what they have to say - this encourages them to share more insightful details about their experiences and skills.

You can also ask open-ended questions that encourage candidates to elaborate on their responses. For example, rather than a simple yes or no question, ask the candidates about how they approached a challenging project or how they handled a difficult team situation. Such questions will give your candidates the opportunity to share specific examples and insights into their problem-solving abilities and teamwork skills.

Another important technique involves avoiding leading questions - like staying neutral and refraining from guiding your candidates to respond in a particular way. This will ensure that their answers are genuine and not influenced by your expectations.

These techniques will help you maintain objectivity and evaluate your candidates’ capabilities and potential fit for your team and company accurately.

Avoiding bias in the interview process

Unconscious bias can inadvertently influence interview outcomes and lead to hiring decisions based on personal preferences rather than objective qualifications. To ensure a fair, unbiased interview process, standardizing your interview questions and evaluation criteria is essential.

Firstly, create a structured interview format where all candidates are asked the same set of questions. This enables consistent evaluation and makes comparing candidates objectively easier. Develop a list of key competencies and qualities essential for the role, and ensure that each candidate is assessed against these standardized criteria.

Consider using blind review techniques, such as redacting identifying information like names, genders, or educational institutions from resumes or applications. This approach helps reduce the impact of unconscious bias, possibly arising from irrelevant personal details.

Finally, diverse interviewer panels can contribute to a more impartial evaluation process. Especially, by involving interviewers from different backgrounds and perspectives, you can obtain a more comprehensive, well-rounded assessment of candidates’ qualifications and their potential contributions to your development team.

Rating and scoring candidates

Developing a systematic scoring system is instrumental in the objective and consistent evaluation of candidates. Assign specific criteria and weightage to different aspects of the interview, such as technical skills, problem-solving abilities, teamwork, and communication.

For instance, you might rate technical interview performance based on code efficiency, algorithmic knowledge, and debugging skills. At the same time, you may use behavioral interview scores could assess their effectiveness at teamwork, adaptability, and communication. By combining these scores, you’ll get a holistic view of each candidate’s overall suitability for the role.

Consider using a numerical scale or a rating system (e.g., a 5-point scale) for each criterion. This helps interviewers quantify their observations and provides a standardized approach for evaluating candidates’ responses.

To make sure your final decision for each candidate is as objective and as comprehensive as possible, gather feedback from all interviewers after the entire interview process. By averaging candidates’ scores and comparing their performance against your predefined criteria, you’ll be able to make data-driven hiring decisions aligning with your organization’s needs and foster a fair, equitable selection process.

When seeking highly skilled software engineers, recruiters should look for candidates with a strong set of skills, including hard skills such as planning, evaluating, creating, and testing code and monitoring its quality, as well as soft skills like planning workflows, problem-solving, and collaborating effectively within teams.

Here is a comprehensive list of some of the most frequently asked questions you might want to ask your candidate in software engineer interviews., Highlight the specific technologies or tools the software developer will be expected to use. For instance, if your company heavily relies on Python for back-end development or JavaScript frameworks like React for front-end development, then make sure to mention them in the job description. With this level of transparency, you’ll be able to attract candidates who have experience with these technologies and are genuinely interested in the projects they’ll be involved in.

A well-crafted job description should also emphasize your company’s culture and values. Being a strong cultural fit can be as important as having the required technical skills - this can lead not only to higher job satisfaction but also to better team collaboration. So, use the job description to showcase your company’s mission, vision, and values.

Candidates who resonate with your company culture are more likely to be engaged, motivated, and committed to contributing to the company’s success. So, if your organization values innovation and encourages a collaborative work environment, include this in the job description., Software developers often encounter complex challenges, which require innovative solutions. To solve those, they may need to use several to use their core competencies. These core competencies play a massive role in building a high-performing software development team. They go beyond the technical skills you may require your software developers to have.

Analytical thinking, closely related to problem-solving, involves the ability to process information logically and critically. Software developers must approach tasks with a data-driven mindset to identify patterns, make informed decisions, and optimize their code and processes.

Look for candidates who can analyze problems from various angles and develop efficient and elegant solutions.

In addition to technical skills, teamwork and communication skills are essential for software developers, especially in collaborative environments. A software developer who can effectively communicate technical concepts to both technical and non-technical team members can streamline development processes and enhance overall productivity.

Adaptability is also a key trait because the technology landscape is ever-evolving. Candidates who are open to learning new tools and methodologies and can quickly adapt to changing project requirements are invaluable assets to any software development team.

Designing technical and behavioral interview questions

To gain a comprehensive understanding of your candidates’ abilities and fit for the role, you can include both technical and behavioral interview questions in the evaluation process. Technical questions can simulate real-world scenarios your candidates may encounter on the job. They can help you assess your candidates’ technical knowledge and problem-solving skills.

For example, you can present your candidates with coding challenges or algorithmic problems that align with the required development specialization. During the technical interview, you can ask your candidates to implement a particular feature or optimize existing code. You can assess their technical prowess and development capabilities by evaluating their coding efficiency and problem-solving approach.

On the other hand, your behavioral questions should delve into your candidates’ interpersonal skills, work ethics, and ability to handle various situations. Using the STAR (Situation, Task, Action, Result) method, you can ask candidates to provide examples of handling challenges or conflicts in previous roles.

For instance, you can inquire about a time when they worked on a challenging team project and how they contributed to its success. By exploring their past experiences, you can gauge their communication style, teamwork abilities, and adaptability in diverse work settings.

Continue to the next section for specific technical, language-specific, and behavioral interview questions, To answer this technical question, your software developer candidate must show their planning, process, and communication or collaboration skills. They should also be able to explain their abilities further by talking about projects where their contributions covered all these bases.

Your ideal candidate must articulate their project management approaches and demonstrate experience in working with larger teams. Candidates experienced in Agile methodologies may be preferable because of their iterative and flexible nature.

For example, they should be able to:

• Outline the components of the project and what role they played.
• Highlight their interactions with other teams and their process of handover and collaboration.
• Detail the difficulties they faced when working in a team and how they overcame those challenges - like whether they encountered personality clashes, inexperienced team members, or meeting inefficiencies.

When your candidate talks about their past projects, they should be able to articulate their most and least favorite parts of collaborating with others. They must:

• Specify cutting-edge collaboration tools, as well as techniques and methodologies they worked with.
• Explain what went wrong with their failed projects, what they learned from those failures, and how they improved on it.
• Remain humble if or when they share their good and bad experiences of working with a subpar team., First, a good candidate will have a thorough understanding of the different testing types. For example, do they know the differences between unit regression and user-acceptance testing?

A potential candidate should have prepared a project or two they have tested thoroughly in the past. They should break the projects into sections and explain the testing type that fits different characteristics. Moreover, they should describe the goals of different testing types and introduce the library or service they used for the test. (Bonus points if they’re able to explain the pros and cons of the library or service and indicate whether they were the one who decided to choose that particular suite!)

It makes sense for developers to include documentation (particularly inline documentation) now. Your ideal developer should be great at documenting functions and issues so that testing runs smoothly., You don’t always need to include this question, but it can help you gauge your candidate’s organizational and prioritization skills., * Industry experience

• Technical skills
• Soft skills
• Key accomplishments

They should also be able to highlight their passion for the job by displaying:

• Excitement - which will fuel their performance
• Passion - which confirms that they’re interested in this job, and
• Eagerness - which will help them get through challenges at work

First, you want to ask your candidate to share information about themselves. Feel free to break the ice by asking some of these questions:

• How did you become interested in software engineering and technology?
• How would you describe yourself as a professional, and how do others perceive you in a work setting?
• Beyond your career, what are some of your hobbies or passions that bring you fulfillment?

Current experience

After you’ve had a chance to get acquainted with your candidate, start diving into the specifics of their current experience. You can ask them to:

• Outline the role they are currently in, their responsibilities, and their achievements (without just reciting your resume).
• Highlight what they are the most passionate about (e.g., working with PMs to perfect the product specs, discussing with colleagues about different tech stacks, and helping others excel in their jobs and career).
• Recount one or two of their job-related projects and/or situations that map onto this job (e.g., collaborating with designers, working with legacy code, implementing best practices, introducing new tech stacks, and mentoring colleagues)., * Why they think the problem was especially challenging
• Why they were determined to solve the problem, regardless of how challenging it was
• How they handled the mental and emotional stress during the process
• Whether they asked for help and collaborated with others in the problem-solving process
• How they came up with the solutions to solve the problem at hand

What to watch out for

• Complaining about having to handle the problem
• Showing how annoyed they were at the problem
• Pointing fingers at others for the problem
• Talking ill of their previous bosses or coworkers

Keep in mind that you’re trying to get a glimpse of your candidate’s past and understand how they might react to challenges should you hire them. Therefore, look for candidates who can also share examples relevant to your company.