Abstract: A financial transaction processing system is disclosed, wherein substantial processing efficiencies are provided with, additionally, a substantial decrease in the size of the executable code. Each transaction processed by the transaction processing system is described by a transaction data descriptor that includes a series of subtransaction data descriptions of actions that can be performed independently of one another. Thus, complex transaction processing logic is substantially removed from the executable code, and instead such transaction data descriptors are processed interpretatively. Moreover, the independence of the subtransactions allows the subtransactions of a transaction to be processed in parallel when performed on a multiprocessor computer.