SAP S/4 HANA has Standard Webservice related to Standard BAPI
Every SAP Customers are using a lot of Satellite system hence Integration is very Important. SAP has understood this demand and hence in SAP S/4 HANA we have Standard Webservice related to some BAPIs also. Hence the Technical Consultant will not have build custom Webservice for the Requirements.
How to Find the Standard Webservice.
Go to Transaction Code SE84