What is Default Value Change in Machine Learning

We all use default values in our code: it could be 0, it could be -1. Maybe your default value of choice is NaN or something else. Code, and especially the model, assume that the default value will not change. 

When a default value is changed without the relevant parties knowing, for example, the data science team, it can result in unexpected inputs and unexpected behavior of a model.

Learn more about how this can affect your model in production.