Replacement of InfoPath form

Dear All,

We have few InfoPath based applications where we are using few things in existing forms:

1. Integrate with SQL

2. .ASMX custom service

3. Integrate with SAP Via middleware

What is the good approach to achieve all this in SharePoint online. What technique should use? What soft language should use? what is good way to connect with SAP data in SP online? Where to host custom REST API if needed?

Thank you in advance for your help.

Br, Hemendra

Hemendra:Yesterday is just a memory,Tomorrow we may never see<br/> Please remember to mark the replies as answers if they help and unmark them if they provide no help