Transformer underwriting model offers a new approval-growth and credit-quality test

Affirm's production transformer-plus-XGBoost underwriting system reportedly lifts completed purchases by 3.4%, improves weighted FPDQ60 AUC gain 1.8x overall and 2.1x for thin-file users, and preserves real-time explainability. The findings strengthen the approval thesis, but longer-term cohort losses, delinquencies, conversion durability, margins, and regulatory scrutiny remain unverified.