`user_id` (anonymized), `age` (18-65), `gender` (M/F/NB/Other), `sexuality` (Het/Gay/Bi/Pan/Other) - `race_ethnicity` (White/Black/Latino/Asian/MENA/Mixed/Other), `education` (HS/Some college/BA/Grad+) - `income_bracket` (5 categories), `location_type` (Urban/Suburban/Rural) - `profile_completeness`