Microsoft is using an Azure Machine Learning–deployed gradient boosted classifier to predict default risk for small business credit applications in Dynamics 365 Finance. The model was strong at launch, but six months later the risk team reports more unexpected defaults while the model’s approval rate has stayed nearly unchanged.
| Metric | At Launch | Current | Change |
|---|---|---|---|
| Precision | 0.78 | 0.74 | -0.04 |
| Recall | 0.81 | 0.63 | -0.18 |
| F1 Score | 0.79 | 0.68 | -0.11 |
| AUC-ROC | 0.87 | 0.82 | -0.05 |
| Log Loss | 0.41 | 0.53 | +0.12 |
| Brier Score | 0.16 | 0.21 | +0.05 |
| Approval Rate | 61% | 60% | -1 pt |
| Monthly default rate on approved loans | 2.9% | 4.7% | +1.8 pts |
You need to design a post-deployment monitoring approach and diagnose whether the issue is threshold drift, score miscalibration, feature drift, or a broader change in borrower behavior. Assume labels arrive with a 60-day delay, so some online metrics are only available later.