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The Map Reducer
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 analytics pipeline applies transformations in two stages. Write a function called map_reduce that takes a list of values, a mapper function that transforms each value, and a reducer function that combines two values into one. Apply the mapper to every element, then reduce the mapped results left to right. If the list is empty, return None.
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