The assignment is to port Apple's Calendar and Contacts system from PostgreSQL to Apigee Usergrid ([url removed, login to view]) as its backend.
Apple's Calendar and Contact server ([url removed, login to view]) is a mature and open source calendar & contacts server. It is written in python. It has its own Authentication/Authorization system as well as integrates with OpenLDAP. The data storage and identity management systems are already abstracted to support multiple providers. We need Usergrid implemented as the back end provider.
All data storage needs to use Usergrid (no PostgreSQL or MySQL).
The system needs to support multiple simultaneous server instances to be fault tolerant.