Construct Validity
Construct validity relates to whether a particular psychometric assessment...
section one
5 Interview Questions for Hiring Software Engineers
Lead consultant at Test Partnership, Ben Schwencke, explains why interviewing software engineers is essential.
IT recruitment, for a number of reasons, is often ranked among the most difficult from a human resources and talent management perspective. Firstly, demand for good software engineers is very high, meaning that experienced developers often have many options for employment. Next, the required skills are too technical for HR or TA practitioners to evaluate using interviews, requiring the help of other IT professionals alongside. Lastly, software engineers often lack traditional interviewing skills, particularly compared to other essential corporate roles.
IT recruitment, for a number of reasons, is often ranked among the most difficult from a human resources and talent management perspective.
In this article, we will provide five effective interview questions specifically for software engineers, designed to evaluate their practical and technical abilities. These questions are likely to require the support of someone with technical expertise, and so we advise using panel interviews.
Describe a challenging software problem you've faced and how you approached solving it.
A compelling response will provide clear context about the problem, detailing its intricacies. The candidate will systematically explain their thought process, the steps they took, and any collaboration or resources they leveraged. Demonstrating adaptability, resilience, and learning from the experience will showcase not only technical skills but also personal and professional growth.
A weak answer might lack depth or specificity about the problem and the steps taken to resolve it. It might be generic, suggesting that the candidate did not fully grasp the complexities of the issue or contributed minimally to its resolution. Furthermore, if the candidate doesn't reflect on lessons learned or how they improved as a result, this indicates a lack of self-awareness and growth.
- 1. What made this particular problem more challenging than others?
- 2. How did you prioritise your tasks during the solution process?
- 3. What did you learn from this experience that you applied to future projects?
How do you ensure the quality of your code when working on a software project?
A robust response will highlight a multifaceted approach to ensuring code quality. This includes a mix of unit, integration, and system testing, as well as the use of automated tools where appropriate. Emphasising collaboration, seeking feedback, and iterating based on that feedback showcases a commitment to excellence and continuous improvement.
A subpar response might rely on generic statements like "I always test my code" without delving into specific methodologies or tools. If the candidate doesn't mention collaboration, peer reviews, or continuous learning, it suggests a potential lack of thoroughness or openness to feedback.
- 1. What testing methodologies do you commonly use and why?
- 2. Can you share an instance where rigorous testing prevented a major issue?
- 3. How do you manage peer reviews and feedback on your code?
Explain a situation where you had to choose one technology stack or tool over another. What factors influenced your decision?
An impressive answer will highlight a thoughtful, systematic evaluation of each technology or tool option, factoring in both technical merits and broader project and organisational contexts. Mentioning considerations like scalability, maintainability, team expertise, and client requirements shows a holistic approach to decision-making. Discussing the eventual impact on the project provides evidence of the decision's effectiveness and the candidate's accountability.
An insubstantial response might focus solely on personal preferences or make broad statements without providing specific reasons. If the candidate doesn't consider the broader project or organisational context in their answer, it could indicate a narrow view or lack of comprehensive decision-making.
- 1. How did you evaluate the pros and cons of each option?
- 2. Were there any external pressures (e.g., client requirements, team familiarity) that influenced your choice?
- 3. How did your decision impact the project's outcome?
How do you approach code optimisation, especially when dealing with performance issues in an existing system?
A solid answer will demonstrate a methodical approach to identifying and addressing performance bottlenecks. It will mention specific tools or methodologies used for profiling and optimising code. The candidate will also display an understanding of the trade-offs involved, emphasising the importance of maintaining code clarity, readability, and the overall health of the system.
A lacklustre response may be vague, only mentioning general concepts like "I look for slow code" without specifying methods or tools. If a candidate speaks only of optimisation without considering the potential downsides or broader impacts, it might indicate a narrow perspective or lack of experience.
- 1. Can you share a specific instance where you identified a bottleneck and addressed it?
- 2. What tools or methodologies do you employ to measure and improve performance?
- 3. How do you balance the trade-offs between optimising code and potentially compromising readability or maintainability?
Describe a situation where you disagreed with a team member about a technical decision. How did you handle it and what was the outcome?
A compelling answer will stress the importance of open dialogue, listening to various perspectives, and finding common ground. The candidate should highlight their willingness to be adaptable, learning from others, and prioritising the project's success above individual ego. Reflecting on the dispute's positive outcomes, such as improved communication or better decision-making processes within the team, showcases growth and maturity.
A weak response might focus on blame or personal disagreements without highlighting the technical facets of the dispute. If a candidate presents themselves as inflexible or unwilling to consider alternative viewpoints, it could raise concerns about their ability to collaborate effectively.
- 1. How did you ensure the discussion remained constructive and focused on the technical aspects?
- 2. Were any compromises made? If so, how did you arrive at them?
- 3. How did this experience influence future interactions or decisions within the team?
section two
Limitations of interview-only recruitment processes for software engineers
When it comes to software engineering, interviews can be difficult to get right. Typical competency-based interviews, which focus on measuring specific behavioural competencies are unlikely to be effective predictors of performance, especially compared to more technical interviews. Consequently, HR and TA are in a poor position to conduct these interviews, and instead only a senior IT professional should be conducting these technical interviews. However, even highly structured technical interviews can only ever tell you what the applicants knows right now, it doesn’t say anything about their potential to develop and grow.
Given that relatively senior IT professionals are required to conduct interviews for software developers, this makes interviews a particularly non-scalable selection tool. Naturally, if an interview requires 3 hours of planning, preparation, conducting, and then feeding back to candidates, 10 interviews will take 30 hours in total. When assessing a relatively high volume of candidates, interviewing takes up a huge proportion of a hiring manager’s time, preventing them from working on their tasks and goals. Consequently, organisations should always consider the tangible opportunity costs associated with performing interviews, and seek more cost-effective alternatives if needed.
In addition to technical interviews, we advise incorporating online psychometric assessments and ability tests when shortlisting software engineers. In particularly, ability tests will be of paramount importance, as software engineering is extremely complex cognitively speaking, requiring a high level of cognitive ability. Unlike technical interviews and software skills tests, ability tests are predictive of future performance, not just performance in the present moment. Consequently, they are a better indicator of potential, which is especially important when recruiting for junior developers and early stage career talent. For more information on our suite of assessments, please contact us directly or register for a free trial.
