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.'

This is the question to design the scoreboard, not the player. A strong answer separates offline gates (AUC, calibration, NDCG) from the online verdict (A/B with revenue, user, and advertiser guardrails), and adds counterfactual replay so you can trust a model before it ever serves a real auction.