Downstream
A hard Python mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- Python
- Difficulty
- hard
- Seniority
- L6
Interview Prompt
You're writing the executor at the core of a small pipeline orchestrator. `tasks` maps each task name to its `deps` (names of tasks that must run first) and `func`, the source text of a lambda that takes a dict of its dependencies' results, keyed by dependency name, and returns this task's output. Run each task once all of its prerequisites have run, return a dict from task name to result, and raise if no valid run order exists because the dependencies form a loop.
Summary
Nothing runs until what it needs has run.
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