Oracle Cloud Applications and SAP4Hana have many similarities regarding extensibility according to the following diagram that depicts at high level the main components of both solutions from an extensibility point of view. Let’s take a look.
Oracle provides REST API’s as well as SOAP web services. Sap provides SOAP and oData, which is, at the end of the day, kind of REST. oData is an OASIS standard with SAP, Microsoft, Dell and others such as IBM behind the scenes.
Oracle provides JET and Visual Builder. Visual Builder is a low-code or citizen programming framework. Visual Builder is built with JET. Technology behing is HTML5/JS, jQuery, Cordova, CSS and the like.
SAP provides SapUI5 as the development framework and Fiori is a set of prebuilt Apps made with SapUI5. SapUI5 is based in HTML5, JS and CSS.
Hope it helps, stay safe!! 🙂