I've been asked to help conduct the first-round interviews for Python developer candidates, but I'm the only person on the team with programming experience. The initial interview will be a 15–30 minute video call, while an outside consultant will handle a more thorough technical evaluation in the second round. What practical questions could I ask to gauge a candidate's Python experience without relying on obscure trivia?
4 Answers
For a short practical exercise, ask them to implement a simple decorator or context manager. Keep the task small and focus on how they reason through it, explain their choices, and handle edge cases rather than expecting a polished production solution.
A useful Python-specific question is to ask how mutable default arguments behave, such as using a list as a function parameter. You can then ask how they would avoid the resulting shared state, usually by using None and creating the list inside the function.
You can also ask about everyday development practices: how they manage dependencies, use linting and type checking, structure tests, or decide when to refactor. Experienced Python developers often have clear opinions here, and their reasoning gives you a better signal than memorized language facts.
Ask candidates to describe a time they inherited messy code and improved its readability or maintainability. Their explanation can reveal how they think about structure, testing, tradeoffs, and working in an existing codebase—often more effectively than trivia questions.
It’s less about whether they use that pattern in production and more about whether they understand why it behaves unexpectedly and can recognize it during code review.