SAP HCI is designed as Integration System-as-a-Company (PAAS) which really helps to combine many impartial programs/apps for a business procedure. HCI can do Cloud to Cloud, Cloud to On-premise, On-premise to On-premise and Hybrid product. HCI features Adapters (Connectivity solutions) which include: Cleaning soap Adapter, IDoc, HTTP, Mail, SFTP,Ariba, oData. https://sap-s-4hana-cloud91468.jts-blog.com/27670150/hana-cloud-integration