Introduction
Hiring technical talent is one of your company’s biggest investments. To do it right, you need to know how to conduct a technical interview that allows you to evaluate candidates efficiently and accurately. Implementing a scalable, consistent technical interview process will not only improve the candidate experience—it will also help you hire top talent faster and give capacity back to your engineers.
Recruiters today face several challenges when it comes to technical interviews. Evaluating candidates’ proficiency in complex subjects without heavy involvement from engineering can be hard. Striking the right balance between technical and soft skills evaluation measures, overcoming unconscious biases, and ensuring consistent evaluations among interviewers also pose difficulties.
At CodeSignal, we’ve seen firsthand that pedigree is often a poor proxy for skill—and well-conducted technical interviews are the key to building winning technical teams. Our technical interview and assessment platform is used by hundreds of top tech employers, helping them accelerate time to hire, improve quality of hire, save engineering time, and reduce biases in technical recruiting.
In this article, we’ll explore what a technical interview is, how these types of interviews are usually conducted, and how to do a technical interview most effectively.
Skip ahead to a section of the guide here:
- What is a technical interview?
- How to prepare for conducting a technical interview
- How to conduct a technical interview step-by-step
- How can technical interviewers correct biases?
What is a technical interview?
A technical interview is a job interview used by hiring teams to evaluate candidates for software development, engineering, and other technical roles that require specialized expertise. Technical interviews often focus on assessing a candidate’s job-relevant technical skills, problem-solving abilities, communication style, and ability to perform under pressure.
By objectively measuring a candidate’s proficiency in relevant technical areas, these interviews help gauge how successful a candidate may be in the role they’re applying for. They help employers determine whether the candidate possesses the necessary technical skills and whether they will be a good fit for the company.
Part 1: How to prepare for conducting a technical interview
As an employer wanting to know how to do a technical interview successfully, you need to start with an understanding of the role you are hiring for, including the specific technical skills and knowledge required. You’ll also need to develop and implement a structured approach to fairly evaluating candidates—before any interviews occur.
Here are some steps to help you prepare for conducting a technical interview:
Decide on a technical interview format
Hiring teams can use several types of technical interview formats to assess a candidate’s technical skills and knowledge, each with its own distinct purpose and advantages. Here are some common technical interview formats and how they are typically used:
- Coding challenges: During a coding challenge, candidates are asked to write, analyze, or debug code. They may also be asked to solve programming problems or complete algorithmic tasks. Typically conducted online, these coding exercises streamline the hiring process and allow companies to quickly identify top technical talent. Technical interview and assessment platforms like CodeSignal contain coding challenges that hiring managers can use, providing employers a platform for objectively assessing candidates’ coding skills.
- System design discussions: This type of technical interview assesses a candidate’s problem-solving abilities through the design of complex systems. Interviewers may instruct candidates to craft a system for a specific use case or discuss the design of a real-world system. For example, you may ask a candidate to design a new app for moving companies or a new feature for Facebook. While coding challenges can be given at all technical levels, system design discussions are typically reserved for senior-level positions.
- Whiteboard problem-solving: In a whiteboard interview, candidates are asked to solve coding problems or design algorithms on a physical whiteboard in front of the interviewer or hiring panel. While this can help hiring teams understand a candidate’s thought process, it can also create excessive stress and performance anxiety for candidates. With their focus on presentation abilities, whiteboard interviews may also favor candidates with strong communication skills over those with stronger technical skills.
- Pair programming interview: In pair programming interviews, the candidate collaborates with an interviewer to solve problems or complete coding tasks in real time. Both the candidate and the interviewer collaborate in a single cloud-based integrated development environment (IDE), with the candidate acting as the “driver” who writes the code, and the interviewer acting as the “observer” who reviews the code and shares in-the-moment feedback. This type of technical interview is often used to evaluate a candidate’s collaboration, communication, and problem-solving abilities.
- Take-home assignment: A technical take-home assignment is a project-based assessment where candidates complete a coding or engineering task outside the interview setting. These assignments provide valuable insights into a candidate’s problem-solving abilities, creativity, and practical skills. However, take-home projects can be time-consuming for candidates, as they may require several hours or even days to complete. Expectations and limits around time should be considered in order to keep highly skilled candidates (with limited availability and many options for employment) engaged in your process.
The choice of interview format depends on the role, company culture, and the specific technical skills and abilities you want to assess in candidates. Combining different formats is also an option and can provide a more holistic evaluation of the candidate’s competencies. Ultimately, companies want to choose a format (or formats) that will allow candidates to most accurately and efficiently showcase their relevant technical skills.
Prepare questions tailored to the role
Good technical interview questions align with the technical requirements of the specific role you are hiring for. Start by asking what skills are needed to succeed in the role. Be precise and thorough, gaining input from hiring team members or subject matter experts (SMEs) regarding the job’s technical aspects. For example, a junior Python developer and a senior DevOps engineer will likely have very different interview questions. Once you identify the core technical competencies critical for success, you can focus your questions on the skills most important to the role.
Writing technical interview questions starts with having a solid understanding of what skills your ideal candidate should possess. And while this does take more effort than copying generic interview questions from sites like LeetCode, thoughtful questions will ensure that your interviews are predictive and fair. Writing interview questions must be so precise, CodeSignal even has a team of assessment design engineers and Industrial-Organizational (IO) Psychologists dedicated to the task. Our team develops Certified Evaluations that accurately evaluate on-the-job coding skills, reduce bias, and eliminate question leaks—so engineering teams can spend less time creating and maintaining interview questions.
Consider real-world scenarios
While technical skills assessments like coding challenges can help you evaluate a candidate’s knowledge of algorithmic concepts and data structures, bridging the gap between theory and practice is essential. Beyond book knowledge, technical hires must understand how to tackle problems in real-world conditions. How do they collaborate with their peers, what is their thought process, and how adept are they at solving problems practically? To assess these areas, it’s crucial to introduce realistic scenarios into the interview process that a candidate may encounter on the job.
One way to do this is by using job simulations in technical hiring. However, creating realistic job simulations is often challenging because the tools software engineers typically use run on dedicated hardware. And this, of course, is often nearly impossible to replicate in a technical interview. However, CodeSignal is one of the few technical hiring platforms that emulates the functionality of a local development environment in the cloud, allowing interviewers and candidates to collaborate in a highly realistic integrated development environment (IDE).
Give your candidate any important resources in advance
A technical interview can be intimidating for even the most qualified candidates due to the uncertainty that often surrounds them. To put candidates at ease, provide them with resources to prepare for the interview. Consider sharing a checklist of steps to take before a coding assessment or tips to prepare for the technical interview. By providing a practice assessment to ensure candidates have the proper technical setup, employers should help candidates know exactly what to expect during a technical interview. Not only will this improve the candidate experience, but it will also ensure interviews truly reflect a candidate’s technical abilities. Choosing a technical interview and assessment platform with resources available to candidates—such as mock assessments and tours of the development environment—can save you time on this step.
Create a process for timely feedback and follow-up
Candidates put a great deal of time and energy into technical interviews—and they deserve timely feedback after an interview. Top technical candidates are also in high demand, and not getting back to them quickly may mean you lose them to a competitor. Creating a process for providing feedback after a technical interview will help you deliver a great candidate experience and improve your ability to hire the best technical talent.
An applicant tracking system (ATS) can help you efficiently communicate with candidates about where they are in the recruitment process. You can also share detailed scoring reports with candidates, which allows them to understand how they performed on a coding challenge. Once candidates complete a CodeSignal technical assessment, for example, they will receive a Coding Report that includes an objective measure of their coding skills and more. Even if an applicant is not the right fit for the role they are interviewing for, providing constructive feedback will help them feel valued, improve their performance in future interviews, and help build a strong employer brand.
Part 2: How to conduct a technical interview step-by-step
Technical interviews can be nerve-wracking for candidates and recruiters alike, so it’s important to go into each interview with a specific plan of action. Whether you need to know how to conduct a technical interview remotely or in person, here are seven steps hiring team members should take to ensure the interview is fair, consistent, and relevant to the requirements of the position:
Step 1: Familiarize yourself with the platform and select or create appropriate coding tasks
Just as candidates will benefit from getting acquainted with your assessment platform before a technical interview, so too will members of your hiring team. Before interviews commence, have each team member take some time to explore the features, coding challenges library, and live coding environment of your chosen platform. CodeSignal, for example, offers validated pre-screen assessments and an extensive, searchable library of over 4,000 coding questions that can be used in live interviews.
Whether you use your assessment platform’s existing question library or create custom questions, selecting coding problems or challenges that closely align with the job requirements and skills you want to assess is essential. Rather than asking all candidates general algorithmic questions, it’s also important that the questions correspond to the seniority of the role. When senior-level candidates are asked questions testing their core programming knowledge—questions better suited for entry-level or junior developers—they can become frustrated and lose interest. And perhaps rightfully so, since these questions often have little relevance to their day-to-day responsibilities.
Finally, before you start interviewing for an open role, make sure you are set up to ask the same questions in the same order for each candidate. This is considered a “structured interview,” and it allows interviewers to remove bias, deliver a consistent interview process, and more easily compare candidates’ responses. While many technical interviewing solutions make it challenging to conduct a structured interview, CodeSignal’s interview templates bring consistency to the interviewing process. With the ability to create templates that consist of the tasks you want to use during the interview, in your desired order, CodeSignal makes it easy for your team to carry out structured technical interviews.
Step 2: Start the technical interview the right way
So, the technical interview has begun and the candidate is raring to go. The first thing you should do is throw a coding challenge their way, right? Well, not exactly. Even though technical interviews are more like tests than behavior interviews or back-and-forth discussions, it’s still important to create a comfortable atmosphere. As with any interview, kick off the technical interview by welcoming the candidate and providing an overview of the interview process. Even though you likely provided resources to help the candidate prepare for the interview, take time at the start of the interview to go over how the interview testing and assessment platform works. This includes walking the candidate through the coding environment, the input/output format, and any additional features or constraints they should know.
Step 3: Begin with a warm-up question or challenge
With the introductions and explanations complete, it’s time to get into the flow of the technical interview. While you might be ready to put your candidate to the test, don’t lob your most challenging questions out of the gate. Instead, begin with a warm-up question or coding exercise that is relatively simple to break the ice and help the candidate get comfortable with the coding environment.
Step 4: Move on to the main coding interview phase
Once the candidate has completed the initial warm-up exercise, design subsequent questions that build upon prior answers. For example, you might first ask the candidate to construct an interface for a simple use case. Once they demonstrate proficiency in that task, you can progress to giving them a more complex use case. This lets you see how candidates approach problem-solving and handle increasingly challenging coding challenges.
You can present candidates with this sequence of coding questions using the interface of your chosen interview assessment platform. Using the platform to create structured interview templates in advance will also help you design and stick to a question order that gradually progresses in complexity. As you ask each question, be sure to clearly explain the problem statement, input/output format, and any constraints or requirements.
Step 5: Live coding and observation
Once you’ve given an applicant a problem statement to solve during a live coding interview, let them take off and start coding. Quietly observe their approach, code structure, and problem-solving skills as they work through the assessment platform’s coding environment. Encourage the candidate to think aloud and explain their thought process as they work in real time. Monitor the candidate’s progress and provide guidance if they get stuck. To minimize subjectivity and bias, however, you’ll want to offer the same guidance to each candidate, focusing on prompting their thinking rather than giving away the answer.
Step 6: Follow-up questions and discussion
Once the candidate completes a coding challenge, ask follow-up questions to assess their understanding of the solution, code optimization, or potential improvements. After all, you don’t want the candidate just to give you a final answer—you want to understand their thought process and how they reached that solution. Discussing the code implementation, any trade-offs, and what lessons they learned will help you analyze the candidate’s problem-solving abilities and communication skills.
Step 7: Use a rubric to evaluate performance
Just as you must use a structured interview framework to ask fair, consistent questions, you’ll also want a structured evaluation process. A well-defined interview rubric with a concrete scoring guide can help you evaluate a candidate’s competencies for a technical role.
Here are four ways to design an interview rubric that will help you objectively assess and compare candidates’ responses:
- Rate skills with a numerical system: Mapping candidate performance to a specific number allows you to create a final score to compare skills between candidates.
- Define what each score means: To ensure scoring consistency across different interviewers, outline the range of scores possible for each skill and which observable behaviors the candidate should demonstrate to achieve each score.
- Include technical and communication skills: Engineers need hard and soft skills to succeed. Consider all the competencies necessary to the role you’re hiring for, and pick the most important ones to include in your rubric.
- Calibrate your rubric through initial interviews: Once you’ve created your rubric, ensure it works as intended. One way to do this is to have each rater score the same interview independently using the rubric and dig into any score discrepancies.
How can technical interviewers correct biases?
We all carry implicit biases, regardless of how objective we try to be. We may never be able to fully eliminate bias from the interview process as long as humans are involved. However, creating structured technical interviews and asking job-relevant, progressive questions can significantly mitigate bias when hiring for technical positions.
While you could develop structured interviews manually, using pre-built interview templates and coding questions is far easier—and a much better use of your engineering team’s time. CodeSignal’s platform, for example, allows you to scale technical interviews while also fighting bias in the recruitment process. With features that help companies develop and adhere to a consistent, repeatable, and job-relevant interview structure, all candidates can be evaluated against the same objective standards.
In addition to using a technical interview and assessment platform, here are a few ways employers can further reduce bias when conducting technical interviews:
Blind resume screening
According to Glassdoor, a blind hiring process—one that omits any identifiable characteristics not related to a candidate’s qualifications for the job—is a well-known way to remove bias from recruiting. By scrubbing details from resumes that may give away personal or demographic information about a candidate such as their age, gender, ethnicity, religion, sexual orientation, or disability, blind resume screening can help keep unconscious bias from affecting early recruitment decisions.
Standardizing the process with structured interviews
A structured interview uses the same questions and evaluation metrics across candidates—and it’s crucial to a consistent and fair recruitment process. By asking the same questions in the same sequence, structured interviews promote equity in the hiring process and allow hiring teams to compare candidates based on their technical abilities objectively. Since many companies involve engineers in technical interviews, using a cloud-based platform like CodeSignal to conduct structured technical interviews can also drastically reduce engineering time spent recruiting.
Avoid biased question wording
Coding questions with unclear or bias-laden wording can confuse candidates and result in an uneven playing field. Removing ambiguous or culturally-specific language—and using only job-relevant examples in your coding tasks—can help you remove bias from interview questions. Leveraging a vendor like CodeSignal, whose team includes technical SMEs and IO Psychologists, can also help you design fair, validated technical assessments that accurately reflect candidates’ skills.
Providing a wide range of coding challenges
Giving candidates various coding challenges throughout a technical interview can help reduce bias and ensure a fair evaluation process. Diverse challenges provide candidates with different backgrounds and experiences an equal opportunity to showcase their abilities. During live coding interviews, the most compelling questions are open-ended and gradually increase in complexity. These questions allow interviewers to avoid leading or limiting candidates while promoting diverse perspectives and ideas.
Final thoughts
With the steps provided in this guide on how to conduct a technical interview, technical recruiters and hiring team members have the insights and best practices they need to interview confidently and effectively. From using structured interviews to avoiding biased questions to implementing a process for post-interview feedback, there are many actions hiring teams can take to improve the technical interview process. But technical interviews also take more than manual effort to be truly equitable and efficient—they require the right technology.
Companies must invest in remote technical interview solutions that allow candidates to properly demonstrate their relevant skills—and allow interviewers to evaluate and compare talent fairly. With CodeSignal’s comprehensive technical interview and assessment platform, organizations can streamline and enhance the entire technical recruiting process. Offering solutions for pre-screening, live technical screening, and live collaborative interviewing, CodeSignal delivers the best candidate experience in a realistic coding environment while helping hiring teams accurately evaluate skill and fit.
Want to learn more about how CodeSignal can streamline your technical interview process and help you make the right hires, faster? Schedule a call with one of our tech hiring experts.