The Lazy Stream
A hard Python mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- Python
- Difficulty
- hard
- Seniority
- L5
Interview Prompt
An upstream export arrives as a `data` list where some slots hold a lone value and others hold a short list of values that got batched together during ingestion. Return a flat list that splices each batched list's contents into its place, leaving everything else exactly as it sits (strings stay whole even though they iterate, and anything nested deeper than one level is left as-is).
Summary
Some slots hold one value, some hold a batch. Level them out.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write your python solution with real code execution
- Get instant feedback and a hire/no-hire decision