DiscussionOpinion

What Big Tech Missed And How Startups Can Still Win

Y Combinator

Alex Lebrun, CEO of Amilabs, discusses his journey building multiple AI startups and explains why world models—AI trained directly on sensory data rather than text—represent the next frontier beyond large language models. He argues that being early in technology requires specific founder strengths, and shares lessons on ambition, fundraising, and the challenge of managing a $1.2 billion seed round.

Summary

Alex Lebrun recounts his experience as a serial founder, having built chatbots (2002, 10 years too early), Wit.ai (acquired by Facebook in 2015), Nabla, and most recently Amilabs, a company building world models for AI. He emphasizes that raising $1.2 billion in seed funding creates massive external expectations that are harder to manage than investor expectations—visibility of progress becomes critical for survival.

Lebrun contrasts world models with large language models (LLMs). While LLMs learn from text—a proxy representation of the world written by humans—world models train directly on sensory data (video, audio, robotics) like humans and animals do. He uses an analogy of someone who has read every book for centuries but never left their room, suggesting LLMs lack grounding in real-world experience. World models, by contrast, learn directly from the world without language as an intermediary.

On the entrepreneurial front, Lebrun explains that his strengths lie in early-stage engineering and product development rather than go-to-market execution, which is why he gravitates toward early technologies. He worked with his co-founder Yann LeCun (recruited while at Meta) to found Amilabs after LeCun approached him about scaling world models outside a large company structure. Lebrun handles execution—securing talent, compute, data, and infrastructure—while LeCun provides scientific direction as executive chairman.

Lebrun discusses the practical challenges of his latest venture: securing GPUs (difficult even with billions of dollars), finding specialized talent, and acquiring training data. He notes that the primary bottleneck is not money but access to compute and rare expertise. The $1.2 billion seed round, while record-breaking, primarily funds GPU compute, making everything else seem inexpensive by comparison.

On strategy and ambition, Lebrun advocates for founders to focus on narrow problems with ambitious long-term visions, rather than trying to solve everything at once. He recounts a story where Mark Zuckerberg proposed hiring 10,000 data annotators (rather than the requested 100) at Facebook, illustrating how large-company executives can push founders toward bigger thinking. Lebrun argues that in Europe, startups are insufficiently ambitious and fail to take enough risks compared to their American counterparts.

Finally, Lebrun envisions a future where helpful robots with common sense are widely available, dangerous jobs become less hazardous, and machines possess genuine grounding in the physical world—outcomes he believes world models will enable.

Key Insights

  • Raising $1.2 billion creates expectations in the outside world that are harder to manage than investor expectations—if people don't see tangible output for 2 years, survival becomes very difficult despite investor alignment on long-term vision
  • LLMs are fundamentally limited because they learn from text written by humans about the world rather than learning directly from the world; this is equivalent to a person who has read every book but never left their room and lacks real common sense
  • Current robots are 'very very dumb' despite advanced hardware because their brains haven't evolved; they are narrow vertical systems that fail dangerously in open environments, whereas world models could enable adaptable, generalizable robots
  • The three primary bottlenecks for building large AI models are smart talent (most concentrated elsewhere), large amounts of data, and GPU compute access—GPU scarcity remains difficult to solve even with substantial capital
  • Founders should choose a very narrow specific problem but maintain very ambitious long-term vision within that narrow tunnel, rather than attempting to solve everything for everyone, which destroys credibility and value provision as a small team

Topics

World models as alternative to large language modelsSerial entrepreneurship and startup timingFundraising challenges and expectations managementFounder skills and early-stage technology positioningAI grounding and sensory-based learningRobotics applications and current limitationsTalent acquisition and GPU compute constraintsEuropean vs. American startup ambitionBuilding ambitious products with narrow initial focus

Transcript

[0:00] I told the team yesterday that the real cost of this 1.2 billion was not delusion. uh the real cost is is the expectations not only are from our investors because I think our investors they they understood and they agree on the long-term vision of the company but the expectations you create in the outside world and if you raise 1 billion and you do nothing for 2 years or or people don't see anything uh coming out of it for 2 years then it's very very hard to survive. [0:33] So we actually met Alex. Uh fun fact, we actually did the same YC batch. Uh back then Alex was building with AI and we were building…

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