How YC helps hard tech founders build fast with less money

Executive overview

Hard tech founders arrive at YC convinced they need $50M before they can prove anything. YC forces them to find the smallest slice of the problem they can tackle in three months for $500k.

The shift is mental: once founders accept that constraint, they move faster, demonstrate real progress, and become fundable. The habit of operating cheaply and quickly persists long after demo day.

The core insight: hard tech has high technical risk but near-zero market risk — if you can build it, the demand is already there.

What YC expects from hard tech companies on demo day

• Revenue is not expected; commercial traction is required in a different form
• LOIs with real logos and significant contract values serve as the proxy for customer demand
• A technical milestone — even at small scale — proves the science and the team can execute
• The Brex framing works well: show what typically takes 12 months and $50M, then show you did it in 3 months for $500k
• The "why you" question matters more than "why now" — hard tech markets are often obvious; the founder is not

Boom Supersonic — LOI as demo day proof

• Blake entered YC with a styrofoam model and a vision to replace the Concorde
• Focused the batch on two things: de-risking the technology and de-risking commercial demand
• Days before demo day, secured a $100M LOI from Richard Branson's Virgin Airlines
• Eight years later, Boom flew its first full-scale supersonic jet
• Lesson: even for a multi-billion-dollar product, one credible LOI from a serious buyer changes everything

Cruise — start narrow, expand the vision with capital

• Kyle Vogt came in with a highway driver-assistance retrofit kit for Audi S4s
• Demo day pitch was the retrofit product, not full self-driving — a commercially achievable near-term path
• Kickstarter-style pre-orders provided commercial validation without needing institutional capital
• Raised a seed round on that traction, then expanded scope dramatically with a Series A
• Acquired for close to $1B within roughly two years — the fastest large exit in YC's history at the time

Astranis — build the satellite in the batch, launch it after

• Core insight: small, single-purpose satellites can do what large expensive ones do, at a fraction of the cost
• Demo day photo showed the actual satellite Ryan built during the three months of YC
• Launched it after the batch via a SpaceX cargo slot
• Now manufactures satellites across the street from the YC office — tours run for current batch founders
• Profitable from early on; telecom satellite revenue is a real business

Relativity Space and Astroforge — ambitious bets with staged milestones

• Relativity's demo day goal: 3D print a scaled rocket engine with real injectors and a working nozzle — not a full rocket
• They fired it up on demo day; in March 2023, they launched the first almost entirely 3D-printed rocket
• Astroforge's ambition: fly to an asteroid, refine precious metals on-site, return them to Earth
• Near-term milestone: fly to an asteroid and confirm high precious-metal concentration
• US law confers ownership rights upon landing — multiple monetisation paths before a full return mission

Climate and energy companies — same YC playbook, different atoms

• Hard Aerospace: fully electric 19-seat regional plane; signed LOIs with airlines by targeting routes that currently lose money and are government-subsidised; now has purchase orders from United and Air Canada
• Remora: retrofits semi-trucks to capture 80% of exhaust CO2; founded by matching a climate-focused operator with the world's only PhD thesis on mobile carbon capture for heavy vehicles
• Seabound: retrofits cargo ships to cut CO2; won LOIs in a notoriously hard-to-enter industry driven by new shipping emissions regulations; completed its first pilot on a live container ship
• SoluGen: started with a beaker of hydrogen peroxide, scaled to garage production during YC, sold product from day one at no loss — unusually capital-efficient for an industrial chemicals company

K-scale Labs and Astra Mechanica — current batch examples

• K-scale wants to build consumer humanoid robots; initial plan required $100M — not viable
• Pivot: open-source the hardware designs, build 10 robots themselves, run their foundation perception model across all community-built robots to gather training data at scale
• Pattern mirrors Apple I — selling plans and boards before there was a company
• Astra Mechanica built an electric jet engine efficient at every speed — a genuine technical breakthrough
• Strategy: innovate on as few components as possible; buy everything else off the shelf
• Commercial focus: launching payloads to orbit first, using that revenue to fund the broader vision (Tesla roadster model)

Why hard tech success rates are not lower than software

• Hard tech carries high technical risk but near-zero market risk — the demand is obvious if the thing works
• Software carries low technical risk but high market risk — nobody knows if anyone wants it
• In aggregate, the expected values are comparable; YC's space portfolio actually outperforms many other segments
• The massive potential upside of hard tech (owning an asteroid, decarbonising shipping) justifies the long odds

The operating habit that matters most

• Founders who learn to move fast and cheap during YC retain that cadence permanently
• The best hard tech companies continue pushing things faster and cheaper than anyone thinks possible long after the batch
• If you can not raise $50M, the constraint forces better engineering discipline — and produces real businesses, not money-raising exercises
• Recruiting is easier for ambitious hard tech companies: great engineers and experts join missions, not the seventh social buying site