Basically we are going to taking a deep dive into the Authorization Code Grant of OAuth2.0. We will be building a user system, client system, encrypting access tokens, decrypting them, dealing with refresh tokens etc etc.. We have multiple systems to build here an authorization server resource server a SPA and an authentication front end end as well. We will be using Mongo for our data storage and Nginx to serve our SPA while node will serve our authentication front end.