C2. Consider the public cloud first for all new applications
Lacking any previous dependencies on legacy systems, application architectures, or design patterns, and assuming that SaaS has already been researched and ruled out, the public cloud should be the first choice for new applications.
As with all computing workloads, new and existing, architecture should be considered in tandem with the selection of a hosting environment. Patterns that would be amenable to running in a public cloud environment are preferred, even if ultimately an application does not run in the cloud.
Once a decision is made to run an application on the public cloud, choice of Service Model (see NIST definition of Service Models4) and level of abstraction within that service model must be considered.