It connect the real world with the blockchain through recognizing the real world event and writing it to the blockchain. Its actual job is to track the TOP 500 largest banks and syncronize their state to the blockchain.
This backend server also tracks the market periodically and send alerting signals if a bank drops more than 10% in a hour and more then 20% in a day. So we can be the first who investigate the situation and can communicate about it.
There are multiple data-source to make the system more fault-tolerant.