Feature Toggle is a nice way to hide and/or handle partially finished functionalities in production environments. This may sound weird for those deploying code to production on demand, but it is quite common to find this situation when practicing Continuous Integration, Delivery, or Deployment.

We have introduced the technique and discussed the pros and cons of using it. We also enumerated some of the typical cases where toggling features can be helpful.

There are many libraries that can help us to implement this technique, providing a lot of capabilities such as using a web interface to handle features, storing preferences in a database, or allowing access to concrete user profiles.

Finally, we have implemented two different approaches by ourselves: a Feature Toggle with a very simple REST API, and using the Feature Toggle in web applications.