AI & Machine Learning
Bug Report
Model with 0.91 AUC offline performs near random online: training-serving skew
Our fraud model scored 0.91 AUC on holdout data and close to random in production. The serving service re-implemented preprocessing in another language: the scaler was refit on each batch, one-hot categories came in a different order and text was not lowercased. Shipping the pipeline with the model fixed it.