Scaling Machine Learning at Uber with Michelangelo

Models are trained and initially evaluated against historical data. This means that users can know that a model would have worked well in the past. But once you deploy the model and use it to make predictions on new data, it's often hard to ensure that it's still working correctly. Models can degrade over time because the world is always changing. Moreover, there can be breakages or bugs in a production model's data sources or data pipelines.