Hello !
I was wondering if you could tell me, is your system at this stage already recording the paypal IPNs and marking the carts/orders as being paid ? Or is this also part of the project, to the selected bidder? I'll be honest, I never worked with Ninja Forms before, but in the end it's php code and, besides understanding the mysql tables used and getting the information for the PDF generation from those tables, the only interaction with the Ninja Forms is just related to coding the response from paypal or adding the "hook" / trigger for the PDF being generated and sent out to the customer) . Let me know if I'm wrong about it.
No upfront payment, but I required a milestone created from the beginning of the project, and released once everything is complete and working fine. I'm available to start working right away.
Regards,
Dragos