Your question is Mobile Experiment with Interference Bias. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You work on a mobile app feature that is expected to affect how users interact with each other and may behave differently across device types. Early internal discussion suggests the experiment could be biased if users influence one another or if performance varies by device.
How would you design an experimentation plan for this feature so you can trust the result despite possible network effects or device heterogeneity? Explain how you would choose the randomization unit, metrics, and analysis approach.