How to create a good problem-solving interview

The real value of a problem-solving interview is that it lets any engineer assess a candidate without needing seniority or exotic puzzles. By zeroing in on three signals-how the candidate reformulates the problem, sketches a high-level plan, and communicates each step-you get a clear picture of their thinking before any code is written. This cuts through the noise of trick questions and focuses on the day-to-day work of debugging, designing, and iterating.

Methodology is the first signal. A good interviewee restates the challenge in their own words, asks clarifying questions, and outlines a solution before touching the keyboard. Communication follows: the candidate narrates their thought process, admits gaps, and discusses trade-offs, showing they can collaborate under pressure. Finally, programming skills are validated through a straightforward algorithm that tests data-structure choice, scope awareness, and function semantics-nothing exotic, just the fundamentals you need on the team.

Choosing the right exercise is critical. Avoid overly complex LeetCode-style problems that only a handful of engineers can solve under stress. Aim for a task that a competent engineer can solve in about fifteen minutes, leaving time for follow-up questions about edge cases, bottlenecks, and optimizations. This balance lets you evaluate the full skill set without the interview collapsing into a single narrow metric.

Involve teammates early: they know which puzzles surface the right discussions and can help refine the exercise. Standardize the interview by preparing a short list of follow-up questions-edge-case probing, input validation, and complexity discussion. When candidates can justify a recursive versus iterative approach, spot off-by-one errors, and reason about scaling, you have a strong data point for hiring decisions.

The payoff is a repeatable, bias-aware interview process that saves time and surfaces candidates who think clearly, communicate openly, and have the core technical foundation needed for your team. Consistency across interviews lets hiring managers compare candidates fairly and make faster, more confident hiring choices.