1. A system, comprising: a memory and at least one processor coupled to the memory; and a modeling and optimization component, executed via the at least one processor, wherein the modeling and optimization component: receives at least one of resource-level metrics from a monitoring component and application-level metrics from at least one application; estimates parameters of the at least one application based on the at least one of the received resource-level and application-level metrics; and automatically and dynamically determines directives for scaling application deployment based on the estimated parameters; wherein at least one of the estimated parameters corresponds to an unobservable parameter of the at least one application and is estimated employing an estimation technique without accessing or modifying the at least one application; wherein the estimation technique continually adapts to dynamically changing system parameters during runtime.