Welcome to your interview.
The question is on your right: Network Interference in Collaboration Test. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
You work on a collaborative design product and are testing a change to sharing or commenting behavior. Because users work in teams on the same files and projects, one user’s treatment experience could affect another user’s outcomes even if that second user is assigned to control. You are concerned the experiment may violate the usual independence assumptions.
When would you worry about network interference in this experiment, and how could it distort the measured treatment effect? How would you redesign or analyze the test to account for that risk before deciding whether to ship?