That sort of already exists in AWS, where Lambda allows you to just write business logic inside the browser without having to worry anything about hosting, and

That sort of already exists in AWS, where Lambda allows you to just write business logic inside the browser without having to worry anything about hosting, and Step Functions allows you to do drag-and-drop various other AWS services into a state machine. Granted, I'm not sure how much utility you can derive from Step Functions if you also don't write Lambda functions.