Ask HN: Discovery and validation of product ideas in B2B and hardtech?

I'd like to spend my time working on difficult or interesting problems. My current line of work doesn't fill that criteria. I see product opportunities in my current field around industry specific reporting tools etc, but this would be far from interesting or technically challenging.

When it comes to idea/product validation, the usual line is to get involved in target market communities and talking to customers ASAP. This seems straight forward enough for consumer/social products, but what are some good methods for validating b2b and/or hardtech products. A lot of hardtech companies/products seem to work in obscurity for years before raising but this seems to go against all startup teaching, and the rest seem to come out of academia. Am I wrong?

Assuming ability to build relevant complex products, is it possible to research industries and develop hard tech products for them without prior knowledge of said industries? What are the best ways to go about that, and any examples?

Any responses much appreciated!