Deciding an ecommerce order in real time is not a fraud-detection problem, it is a pricing problem: whoever carries the chargeback also carries the cost of every good customer they turn away. This engine chains three specialist sub-models — address manipulation, IP and device, basket composition — into a consortium model that also sees cross-merchant velocity, then reports the exact log-odds contribution of every signal. Move the thresholds and watch net margin, not just fraud, respond.