Ask HN: Building a Hard Product

I'm a huge fan of YC and other popular ecosystem content. But most of it skews towards simple products.

Does anyone have advice for people working on challenging tasks (which you couldn't get an MVP done with a $500k seed)?

Specifically: I've used my first company to fund progress on a hard problem. So it's pre launch but significant Dev resources put in, I don't think there's any obvious fundraising path for this situation