YC AI Startup School 2025 – Highlights

4 months ago 6

If you have been reading this substack, you’ll know that this post is different from the others here:

  • It’s not specifically about chips

  • It’s from the present (Not the 1960s like one of my posts)

But AI is at the center of tech today, and plays a big role in the semiconductor industry too. I got an opportunity to attend YC’s AI startup school, and here are some learnings from the speakers.

Here’s the list for you to quickly navigate through:

  • This is a great time for the technology industry: Intelligence can be accessed using an API

  • It is also a time for great agency: every industry is changing

  • OpenAI wasn’t built to be big - things that become big usually don’t start that way

  • Today, there is a product overhang in AI: which means models are progressing faster than applications using them

  • Vision for GPT-5 and beyond: Multimodal (image, code, video) input and output + much better memory functions

  • In knowledge work, there is a pattern: Work few hours, wait for feedback, and repeat. This kind of work is perfect for AI agents

  • Open AI’s hardware product vision: A better interface than the smartphone to interact in the real world

    • We have only had 2 big computer interface revolutions so far: Mouse, and Touch. The 3rd will come with AI

  • If the current trend continues, the creation of GPT will be seen by future generations like the invention of the transistor

  • His hiring philosophy is simple: Hire smart, driven people with track record of getting things done

    • In the next 10 years, small teams with big agency will be the most successful

  • His two personal interests in the 2010s were AI and Energy. Today, they are interlinked - we are converting energy to intelligence.

  • Favorite startup advice: Be contrarian, but right (from Peter Theil)

    • It’s very hard to do - When GPT1 came out, Elon Musk said it had 0% chance of success.

    • You just got to keep going, it’s going to be tough

  • He never sets out to build something great - just wants to build something useful

    • When the internet was happening, he just wanted to be a part of it. Applied to get a job at Netscape, but couldn’t get it. So he started something on his own.

  • 2008 was his toughest year - Spacex’s 3rd launch failed, and Tesla was running out of money. At that time, everyone said Elon was an internet guy who shouldn’t try real engineering

  • It’s important to build truth seeking environments in companies - you cannot fool math and physics

  • “Don’t inspire to glory, inspire to work”

  • To build a new AI model, you just need access to three things:

    • Compute

    • Unique data

    • Talented people

  • Intelligence is very rare - it is possible that we are the only species to possess intelligence. That makes it even more important that we are multi-planetary.

  • He predicts that in the next 100 years, there will be more humanoid robots than the human population

  • The ultimate measure of AI shouldn’t be intelligence or AGI - it should be the amount of economic growth that AI can drive

    • He doesn’t believe in anthropomorphizing AI (i.e. giving it human traits) - AI is just a tool

  • Be open minded that the last big algorithm breakthrough in AI is not done - LLMs are not the end, fundamental AI research still matters

  • AI isn’t going to take away software engineering jobs - instead, the traditional SWE role would change to something like “Forward Deployed Software Engineer” (FDSE), a role pioneered by Palantir

    • In the past, typist (someone that uses the typewriter) was a job - now everyone does it. Software engineering will become like that too

  • The most important factors in AI deployment are going to be: Privacy (for individuals), Security (for organizations), and Sovereignty (for countries)

  • Microsoft’s breakthrough in Quantum computing is massive - they have finally solved for a stable Q-bit

    • Today, AI is helping make Quantum computing better. In the future, Quantum computing will enable better AI

  • Access to copilot has been the best intervention ever in the field of education, making it the one domain that Satya is watching out for

  • One lesson he learnt in his career: Do every job like it’s the greatest job you ever had - don’t wait for your next promotion

  • His favorite question while hiring: Describe how you managed a project that was going nowhere - a good answer would highlight three key skills:

    • Can you solve a problem you are faced with

    • Can you bring clarity to an uncertain situation

    • Can you enable a team to work together

  • Advice to anyone building products: Build something that makes you feel empowered

  • Perplexity’s next big bet is the browser - agents are going to be like the different open tabs you have right now

    • They have partnerships with a lot of websites to make this work

  • Triaging and fixing bugs is an important skill, even as a CEO

  • You can’t strategize your way to success - any smart idea will get copied. You just have to work incredibly hard

  • Competition is a great thing, because it tells you that something is worth doing

  • He started perplexity without a clear idea of what to do - founders are advised against this, but it is important to just start something

  • Competing with ChatGPT is hard; competing with Google is easy

  • AI apps have not figured out how to have network effects yet

  • Perplexity’s profit margins will never be as high as Google - no company will have such profit margins anymore

  • Whenever he feels like failing, he goes to Elon Musk’s video about failure

  • She started with a simple goal: How to make machines see. The lack of data to solve this led to the Imagenet dataset.

  • Alexnet was a big AI breakthrough, but it was also a big hardware breakthrough - it was the first time two GPUs were put together to run a workload

  • A lot of her research draws inspiration from the evolution of the human brain - her new venture World Labs aims to solve the problem of Spatial Intelligence

    • Language is purely generative - it does not come from nature. So language alone cannot approximate the world, and get us to AGI

  • She pursued her early research with newer professors in the field - taking such risks matters

  • Graduate school is a place where you can be purely driven by curiosity. But if you are running a startup, you won’t have that freedom

  • She was an immigrant at spent her 20s running a laundromat. Her advice to anyone feeling like a minority: Develop an ability not to over-index on it. Gradient-Descent your way to success.

  • This is the third big shift in software - today’s engineer should be fluent in all three

    • SW 1.0: Code (to program computers)

    • SW 2.0: Weights (to program neural networks)

    • SW 3.0: Prompts (to program LLMs)

  • LLM Analogy 1: It is like a utility (ex. electricity)

    • Building the grid is like training, but instead of serving electricity, it serves intelligence

    • Your access is metered (cost per token)

    • There are few big providers to switch between

    • When an LLM goes down, it feels like a power outage

  • LLM Analogy 2: It is like a fab

    • The capex to train is huge

    • Each model has it’s own secret recipe (like TSMC/Intel do)

    • Some users go fabless (use general purpose Nvidia GPUs); others manufacture in-house (like Google TPUs)

  • LLM Analogy 3: It is like an OS

    • There are closed and open ecosystems (like Windows vs Linux)

    • Different applications can be built on top of them

    • Easy to pirate (Once trained, cloning an LLM models is like stealing a CD for Windows)

  • LLM Analogy 4: They mimic human psychology

    • Hallucinations

    • Jagged intelligence

    • Anterograde amnesia

  • Unlike most breakthroughs in computing, which started with defense or government contracts, (HDLs too, as I covered in one of my posts.) LLMs started with consumers - which is something very new for the computing industry

  • AI will support different levels of autonomy

    • Augmentation (like code/image generators)

    • Partial autonomy apps - like Github copilot/Cursor (coding), Perplexity (search)

    • Full autonomy - we are not there yet

  • All software is going to at least be partially autonomous: So build interfaces for LLMs, not humans

    • For example, product documentation should have markdown in addition to plain text/images - LLMs can access them more easily

    • Operator is a great way to control a computer - but it is too expensive to use for everything - so in the near future, we need better LLM interfaces

  • Karpathy first rode a fully autonomous car in 2013. Yet, we still don’t have full self driving. That’s because there is always a big gap between demo and product

    • Don’t think of it as the year of Agents, think of it as the decade of Agents

  • Execution speed is one of the strongest predictor of a startup’s success

  • Today, the biggest opportunity in AI is at the application level - not at the model, cloud or chip level

    • Specifically, a new agentic orchestration layer is forming - every application would need this

  • Vague ideas are always seen as right, but are always wrong. With concrete ideas, you get clear feedback about right or wrong.

  • The ratio of product managers to engineers will change in the near future

    • Today, on average, we have 4 engineers per product manager

    • In the future, there would be 2 product managers for each engineer

    • So as an engineer today, it is important to have better product instinct

  • Think of building AI products like building a structure with Legos

    • The more blocks (i.e. underlying libraries, models, and so on) that you have, the better your outcome would be

  • AI will push the speed of building products by 10x, so moats will not exist anymore. Brands will be more defensible in the future.

  • Why AlphaGo won?

    • They had the same public data as everyone

    • They used a 128 core TPU to run experiments (which is underwhelming compared to today’s LLMs)

    • It was all about ideas from the team - that made the difference

  • Trust is built through word of mouth - put your work out there and get feedback

  • To publish papers in academia, you need ideas that work and are also beautiful. In industry, you just need a working idea

  • To build a low cost AI product: think about how you can reduce the cost of failed ideas

  • Narrow AI systems will win out eventually (this is different from what Jared Kaplan said)

  • It’s easy to come up with dogma - instead, be ruthless and empirical

  • In traditional robotics, a robot is trained to function in very specific environments. But the goal of her new company is different - Build a robot to do anything

  • For LLMs, scale is the most important - more data + GPUs usually means better models. But to build robots, we need the right kind of data - with sufficient diversity

  • In her talk, she walked us through the steps they followed to train a laundry folding robot

    • But none of the steps followed were specific to laundry folding - they just involved a gradual increase in difficulty level - this can apply to any task

  • The foundational models used to train such general robots is called a Vision Language Model (VLM). It works like this:

    • The robot processes user input along with vision input from cameras

    • The VLM uses this data to generate language commands describing how the robot should respond

    • These language commands are used to control the robot

  • To make their robots more robust and handle open ended prompts - the same VLMs were used to generate synthetic prompts, and these prompts were used to train the VLM

  • She believes general purpose robotics will be more successful than purpose built robots, since the foundational VLMs will keep getting better

    • This was a lot like what Jared Kaplan from Anthropic mentioned in Day 1 about LLMs

  • The time taken for a human to do the same task and AI can do is doubling every 7 months - this is like Moore’s law.

  • Scaling laws will continue to grow - if teams find that scaling laws are failing, it means their training methodology is flawed.

  • To prepare for an AI future:

    • Start building technology that doesn’t work now - by the time you are done, AI would have caught up (similar to chip designers using Moore’s law)

    • Use AI to integrate AI - this is the only way to keep up

  • There are two types of tasks

    • Tasks that can be done with 70-80% accuracy - AI already excels at these

    • Tasks that need 100% accuracy - this will be solved by future AI

  • The real value of AI will come in knowledge tasks that needs us to put information from different sources together - like Biology

  • When integrating AI into existing businesses, one needs to think carefully about the bigger picture - for example, when the electric motor was invented, it was not used to make the steam engine better - instead, an electric engine was redesigned.

Personally, I loved this talk - Varun walked in with no slides, and simply had a candid conversation with the audience.

  • His first company was Exafunction - which build GPU virtualization software

    • It was quite successful and was used by a lot of autonomous vehicle companies

    • Their USP was to abstract away underlying hardware architectures - but with Nvidia gaining dominance, they felt this application wasn’t valuable. So they pivoted

  • They came up with Codium, a Github co-pilot alternative. Later, this became Windsurf, an agentic IDE.

  • His advice to founders: Be irrationally optimistic, but uncompromisingly realistic

  • To stay ahead of the curve, build products where 50% of the ideas don’t work today - by the time you finish, AI would have caught up and everything will work

  • The reason startups win over big companies is: startups are desperate, if they fail, the company dies

  • Strategic moats and switching costs are dying - don’t go by traditional VC advice

  • There are a lot of companies in the world that are still technology starved - this is your opportunity

  • When asked how he manages the stresses of being a founder, he said: “I don’t manage it. There is no way to escape it. If you fail, just get up and keep going.”

  • If we have tasks that humans do that AI cannot - that means we do not have AGI

  • Scaling laws will not get us to AGI (Contrary to what to Sam Altman and Jared Kaplan said, actually)

  • There are two types of data abstraction

    • 1. Value centric - abstraction in the continuous domain

    • 2. Program centric - abstraction in the discrete domain

    • Today’s AI like transformers work well in the continuous domain. But for AGI, we need AI that can handle both domains

  • AI will have a second movers advantage - be confident if you want to build consumer AI applications even today

  • The world will soon enter mass amateurization: what an expert can do today, will be done by AI soon. With agents, these tasks can be done continuously for years

  • Don’t just focus on AI applications that give immediate feedback - like Chatbots. Consumers are ready to wait for hours if they get value out of AI

  • To identify opportunities, think about “what-ifs” in the future. For example:

    • What if nobody drives a car

    • What if everyone has a personal robot

    • What if we can never say what’s real

  • Recommended reading: https://andrewchen.com/the-next-feature-fallacy-the-fallacy-that-the-next-new-feature-will-suddenly-make-people-use-your-product/

  • Everyone says focus is important. But if you are running your own company, you need to focus on a lot of different things. It’s not easy.

  • If you are building something today, build it assuming AGI is coming in 2 years

  • There will be a big difference between products built as “AI first”, vs existing products that retrofit AI

  • There are many open questions about the AI-centric world we are entering

    • Will software become a commodity? Do you only need product managers?

    • What’s the point of downloading an app if you can generate an app on demand?

    • How can users ensure an AI agent is right if everything happens under the hood?

  • Some companies will have an advantage in the AI era

    • Companies with data and data creation opportunities (Meta, Reddit)

    • Companies with secret recipes (like TSMC, ASML)

I hope you found my notes to be useful, especially if you were not able to make it to the event. Many of these talks were also recorded, and I urge readers to check them out here: https://events.ycombinator.com/ai-sus

As usual, please share this post with someone that it might benefit. And subscribe to stay tuned for upcoming posts.

Read Entire Article