I’m using asp.net web forms for my rule engine. All of the server side code is in C#, but I think VB could be used as well. You could do something similar using a SmartApp to expose SmartThings API endpoints and VB code on your end to receive data/send commands.
Link to the relevant documentation for calling web services: http://docs.smartthings.com/en/latest/smartapp-developers-guide/calling-web-services-in-smartapps.html?highlight=httppostjson
Link to my rule engine post if you’d like more info on that: