Very interesting article series. I've just started to look into the OAuth 2.0 options supported by Caché. We are considering it as a method to secure an Angular (2+) application for communition with a Caché REST backend.  Do you know if anyone else testing/using a similar approach? 

I noticed that there are a few missing images in the AUTHSERVER section. Would it be possible for you to add these to the article again?