Techniques to leveraging distributed ledgers for integrating heterogeneous database systems independent of underlying legacy systems are described herein. Heterogeneous database systems may be integrated to generate a desired analytics report. In one embodiment, DApps (i.e., smart contracts) and database drivers may be deployed to implement just-in-time data mapping in smart contracts to save substantial time in integrating these heterogeneous database systems. With the smart contract approach, the database drivers may be configured to port only the key data that are needed to be processed based upon, for example, on business considerations. As a result, only data fields that are needed may be mapped and converted into smart contracts. Because the data needed may be dynamically mapped to the inputs specified for the smart contract, which in turn handles posting to the distributed ledgers, changes to the inputs are isolated to the smart contract, rather than forcing a schema redesign.