While a fusion reactor can't be built in three months, YC pushes hardware and deep tech founders to create a tangible Minimum Viable Proof. This forces them to de-risk the venture by hitting a critical milestone, such as building a small-scale desert prototype or securing key letters of intent, proving traction on a non-obvious timeline.

Unlike traditional software development, AI-native founders avoid long-term, deterministic roadmaps. They recognize that AI capabilities change so rapidly that the most effective strategy is to maximize what's possible *now* with fast iteration cycles, rather than planning for a speculative future.

Visionary founders often try to sell their entire, world-changing vision from day one, which confuses buyers. To gain traction, this grand vision must be broken down into a specific, digestible solution that solves an immediate, painful problem. Repeatable sales come from a narrow focus, not a broad promise.

Frame moonshot projects like Google's Waymo not as singular bets, but as platforms for innovation. Even if the primary goal fails, the project should be structured to spin off valuable 'side effects'—advances in component technologies like AI, mapping, or hardware that benefit the core business.

In a rapidly evolving field like AI, long-term planning is futile as "what you knew three months ago isn't true right now." Maintain agility by focusing on short-term, customer-driven milestones and avoid roadmaps that extend beyond a single quarter.

A visionary founder must be willing to shelve their ultimate, long-term product vision if the market isn't ready. The pragmatic approach is to pivot to an immediate, tangible customer problem. This builds a foundational business and necessary ecosystem trust, paving the way to realize the grander vision in the future.

For deep tech startups aiming for commercialization, validating market pull isn't a downstream activity—it's a prerequisite. Spending years in a lab without first identifying a specific customer group and the critical goal they are blocked from achieving is an enormous, avoidable risk.

Moving from a science-focused research phase to building physical technology demonstrators is critical. The sooner a deep tech company does this, the faster it uncovers new real-world challenges, creates tangible proof for investors and customers, and fosters a culture of building, not just researching.

Startups with noble, future-oriented visions often fail by trying to sell the vision itself. Success requires finding a tangible, immediate "attack vector." Tesla's vision was clean energy, but its first product solved the demand from wealthy buyers wanting a high-status alternative to the Prius.