Graph + gradient-boosted ensemble cut fraud chargebacks by 31% at under 40ms p99
NeoRisk’s rule engine missed coordinated mule rings and device farms — chargebacks spiked after a Diwali promo despite static velocity caps.
Feature store on BigQuery + XGBoost + shallow GNN over device-merchant edges, calibrated thresholds per corridor, shadow mode → canary → full cutover with drift monitors.
- Explainable risk bands for ops review queue
- Real-time scoring API on Cloud Run + Redis hot features
- Weekly backtest harness + PSI alerts on top-20 features
- Human override hooks with full model version audit
- IMPS / UPI channel-specific calibration
- RCA dashboards for false-positive tuning