Your question is Causal Onboarding Impact on Retention. 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 changed the onboarding flow and saw better retention afterward. The concern is that the lift may reflect selection effects or broader user mix changes rather than the onboarding itself.
How would you evaluate whether a change in onboarding is actually causal, rather than just correlated with better retention?