Software as a Service (SaaS) services featuring software for adding interoperability as an additional two layers atop the traditional enterprise stack, namely, the Big Data Layer and Interop Services Layer, which provides downloadable software services hosted on public or private cloud environments to make interoperability between software systems a non-obtrusive orthogonal concern, rather than a point-to-point direct integration concern, by providing generic input-output adapter services, a shared source of truth with a background means to propagate it, and unified identity management at a granular level to ensure idempotent semantics of truth propagation