I just ran across SquareSpace today. It looks as if it's a perfect for what I need to do.
The absolutely critical thing for me is to be able to connect to my national tax office for submitting electronic filings.
Using NodeJs/Express I have already developed and put into production, on my own VPS, all the JSON TO XML, XML signing, SOAP wrappers, WebService connections etc. that are required for this.
Will SquareSpace allow me to connect to the tax department's Web Services?
Will it be possible to intercept (or suscribe to) invoice creation in order to launch the corresponding electronic invoice preparation, submission, validation/verification, mailing to customers?