How to test ML models in the real world

How often do you test ML models in a Jupyter notebook, get good results, but still cannot convince your boss that the model should be used right away? Or maybe you manage to convince her and put the model in production, but you do not see any impact on business metrics? Luckily for you, there are better ways to test ML models in the real world and to convince everyone (including you) that they add value to the business. In this article you will learn what these evaluation methods are, how to implement them, and when should you use each. We, data scientists and ML engineers, develop and test ML models in our local development environment, for example, a Jupyter notebook.