ads ranking

Ads ranking is where calibrated probabilities meet hard latency and money. The signal is knowing that CTR must be calibrated (not just ranked), the feature and serving design, and the auction context. Here is the design that goes beyond 'train a classifier.'

Separate offline gates (AUC, calibration, NDCG) from the online verdict (A/B with revenue and advertiser guardrails), plus counterfactual replay between.