The Forward Fill

An easy Python mock interview question on DataDriven, with an AI interviewer who asks follow-up questions and a hire or no-hire decision at the end.

Domain
Python
Difficulty
easy
Seniority
L3

Interview Prompt

A sensor export in `values` records dropped readings as `None`; return it with every gap filled by the most recent reading before it, keeping the same length.

Summary

Patch the gaps in a noisy sensor stream.

How This Interview Works

  1. Read the vague prompt (just like a real interview)
  2. Ask clarifying questions to the AI interviewer
  3. Write and run your Python against test cases
  4. Answer the interviewer's follow-up questions, then get a hire or no-hire decision