His about page has a great description, including inventing coworking:
I've worn many hats in my career, whether as a tech lead, a product engineer, a startup founder, or a full stack software engineer. I have a long tradition of untraditional, cross-disciplinary innovation across fields. Earlier work includes having started Coworking, which grew into an international grassroots movement to establish a new kind of workspace for the self-employed, with more than 15,000 coworking spaces now open globally.
Quotes
Y Combinator is predicated on startups that require low capitalization since most of the technology they depend on is already mostly developed. This was true pre-2015 where startups depended on commodity open source software, the smartphone capitalized by Apple and others, cloud software capitalized by Amazon, Google, etc. Post 2015 that “tech seed corn” had been used up, leaving just difficult deep tech startups around that need very high capitalization and a focus on developing hard, risky technology. The YC model doesn’t work for those kinds of startups, and is focused on the last tech war.