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The Slow Leak
A medium Python mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- Python
- Difficulty
- medium
- Seniority
- junior, mid
Interview Prompt
Our ingestion layer receives data from multiple upstream sources, each wrapped in its own iterator. Some sources nest iterators inside iterators. Write a function called flatten_iter that takes an iterator which may yield either values or other iterators, and returns a single flat list of all leaf values in order.
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