Unlike software, where customer acquisition is the main risk, the primary diligence question for transformative hardware is technical feasibility. If a team can prove they can build the product (e.g., a cheaper missile system), the market demand is often a given, simplifying the investment thesis.
Engaging with founders a month before Demo Day, even without a formal pitch, provides a vital baseline. Witnessing their spectacular progress over that month creates a powerful second data point on execution velocity, making the investment decision far easier and more informed.
A company with over $9M ARR was initially ignored by investors because it didn't fit the typical early-stage YC profile. Once its revenue was revealed at Demo Day, it became the hottest deal, showing that non-traditional, more mature companies in YC can be overlooked champions.
YC now provides founders an investor's conversion rate (meetings vs. checks). A low rate signals to founders not to prioritize that meeting, forcing VCs to abandon a "catch-all" meeting approach in favor of being highly selective upfront to avoid damaging their reputation within the ecosystem.
Y Combinator's deal flow has become so dominant that VCs who previously avoided it now attend Demo Day to stay competitive, with some even considering investing against their fund's explicit mandate to avoid missing out on top-tier companies.
The most sought-after YC companies have rounds that fill and oversubscribe on the first day of fundraising, often within hours. This extreme velocity means VCs who require multiple meetings or lengthy diligence will lose the deal, necessitating a process built for one-call decisions.
Investors don't need deep domain expertise to vet opportunities in complex industries. By breaking a problem down to its fundamentals—such as worker safety, project costs, and labor shortages in construction—the value of a solution becomes self-evident, enabling confident investment decisions.