What does it mean to test in production? Simply put, testing in production means testing your features in the environment where your features will live. So what if a feature works in staging, that's great, but you should care if the feature works in production, that's what matters.
An excellent tool for testing in production is feature flagging. Feature flagging allows you to separate your code deployment from your feature release. So, when you use a tool like future flagging, you're able to target specific users to see your feature, and you can test your feature and make sure it works and fix any bugs.