What the Day Left Open
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
Interview Prompt
A brokerage's position-keeping service replays the day's executed `trades` to reconstruct each account's holdings. Each trade names a `ticker`, a `side` of `buy` or `sell`, and a share count, where buys add to a position and sells subtract from it. Return the net shares held per ticker, dropping any ticker whose position was fully closed out by the close, and keeping the tickers that went net short.
Summary
Every fill moves a position. Reconstruct where the book settled by the close.
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