Public cloud adoption is mainstream today, but only a small fraction of core business applications run in a public or private cloud. In 2019, a major transformation of legacy apps using powerful container-based, cloud-native digital application platforms will commence. Cloud spending will spike, as many infrastructure and operations (I&O) professionals and their enterprises eagerly adopt cloud tools and services wherever and however they can. Buckle up: The cloud ride is accelerating. This report outlines Forrester's five key predictions that will shape the cloud computing market for 2019.