Finally I've started up my own project.
I am going to use Google App Engine and, Github as environment.
I choose polymer for UI and java as backend system under Google App engine.
This project will step through followings
1. Setup Google App engine & Github project
2. Initialize Google App with Polymer and Java(Spring)
3. Prepare for unit test covering UI and backend component
4. Prototype SNS Collaboration System
5. Getting on development.