Validate Features That Predict User Retention

You have user records with signup time and plan type, plus timestamped user events. You are asked which features might predict retention and how to establish confidence in their predictive value. Candidate ideas include event count, active days, plan type, and signup weekday.

Describe an exploratory and modeling approach. Define the prediction time and retention window explicitly, explain how features are constructed without leakage, and show how you would test whether the features add useful signal. The retention definition is not fixed: make your chosen definition and assumptions explicit.