The following graphics provide an overview of the technical system landscape for SAP E-Recruiting.
Using Web Dynpro ABAP as the interface technology means that it is possible to run front-end and backend together on one system or separated on different systems for the candidate scenarios.
Front-End and Backend on One System
Front-End and Backend on Different Systems
Front-End and Backend on Different Systems (SAP E-Recruiting Integrated with ERP)