@yashrajbothra I agree with @adunsulag re. moving from LTS to LTS unless 5.x introduces a brand new component that solves show stopper types of issues facing an application.
For your summer project you can consider bringing in a full featured support for Sessions. Few areas currently lacking :
- Most of $Globals belong to $_session
- No caching so globals.php loads 100s of globals every time.
- No mechanism to share state.
There are several libraries that can be leveraged for this. We use HybridAuth that includes well designed session management layer.