Footprints in the Feed
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
- L4
Interview Prompt
You're rolling up raw feed-handler log lines in `lines`, each a CSV row of `date,process,host,log_message,bytes`, where the `process` name carries the exchange as its leading token (so `nyse_feed_handler` is an NYSE process and `nasdaq_market_data` is a NASDAQ one). Roll the byte counts up two ways in one pass: total bytes per day, and total bytes per exchange within each day. Return both rollups together, the per-day totals first.
Summary
Every trade left a footprint.
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