I'm working for a company that does DMS Things™ and processing incoming PDFs (for mailroom applications or invoice processing) is one of our core projects. Given that this is the closest submission to my day job ever, I'm really curious about your project.
Your online presentation looks great. The 'layout designer' if you will, the 'where are important things' screens look slick.
I do wonder how you assign those settings to incoming PDFs though. Is it the user's responsibility to say 'This PDF? I told you how/from where to extract data before'? Or do you have some classification system that stuffs the PDFs into buckets (say, by vendor) and templates are assigned to those?
How many PDFs that you encounter contain text (vs. scanned/image only documents)? For us, while the former certainly rise in popularity, the latter are still far too common/more prevalent.
Our solution is mostly on-premise so far (online offerings are the current focus of development) and we're quite OCR heavy, using a bunch of non-free engines and vote between the results. We also have dynamic templates, allowing rule sets containing rules like 'The total amount is a number satisfying format X, usually right or below a string containing "Total"' (and our invoice processing solution basically comes with rules like these preconfigured for various countries).
Are your templates using absolute coordinates/regions? You mention your 'unpaper' feature - do you fix/deskew both images and regions for misaligned pages?
(I won't mention any company/product names, because I don't want to advertise or hijack the thread. Nor do I need to connect my HN account ~directly~ with my employer)