There are provided systems and methods for hardening of rule data object version for smart deployment. A service provider, such as an electronic transaction processor for digital transactions, may utilize different decision services that implement rules for decision-making of data including real-time data in production computing environments. Rules may correspond to coded statements that perform an automated decision-making service for the computing services and platforms of the service provider. When writing rules different variables for data objects are used, which are updated over time. Thus, a rule authoring application may be updated over time to have more and newer variables, which requires updating of the decision services. To optimize updating of the decision services when deploying new rules, the service provider may determine compatible versions of specifications for the variables. Thereafter, the service provider may determine whether a device service's variable specification requires updating.