What the Day Left Open
A medium Python mock interview question on DataDriven, with an AI interviewer who asks follow-up questions and a hire or no-hire decision at the end.
- 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.
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 and run your Python against test cases
- Answer the interviewer's follow-up questions, then get a hire or no-hire decision