Accumulative loyalty system "Gophermart"

The system is an HTTP API with the following business logic requirements:

• registration, authentication and authorization of users;
• getting of order numbers from registered users;
• registering and maintaining a list of transferred order numbers of registered users;
• accounting and maintenance of the registered user's accumulative account;
• checking received order numbers through the loyalty point system;
• accruing for each eligible order number the reward due to the user's loyalty account.

Specification can be found here.