Systems and methods are provided for storing, sorting, and analyzing account transactions in a payment network, and for real-time data analytics. One embodiment of a real-time data storage and analytics system includes a payment network that collects and processes account transactions. The system also includes a first data cluster that includes a first data structure. The first data structure stores a set of the account transactions. Additionally, the system includes a second data cluster that in turn includes a second data structure. The second data structure stores account transactions for new account and account transactions for which there is insufficient space in the first data structure. Moreover, the system includes an application engine that generates a score for an account based on transaction data associated with the account transactions for the account.