@ylecun
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Founder/Chair, AMI Labs; Professor, NYU; Partner, 224 Ventures; Ex-Chief AI Scientist, Meta. Researcher in AI, ML, Robotics, etc. ACM Turing Award Laureate.
New York
Joined June 2009
- Tweets27.9K
- Following800
- Followers1.3M
- Likes33.1K
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I do not write posts on X.
I tweet links to posts on other platforms.
I like and retweet (occasionally)
I comment on friends' tweets (rarely)
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Yann LeCun retweeted
Looking for a PhD program where you can study computational neuroscience? NYU has a fantastic array of researchers covering the field, and we'd love to consider your application:
groups.google.com/g/systems-…
Yann LeCun retweeted
Thanks to Trump, the United States sticks out as the only major economy where planet-warming pollution increased dramatically last year, according to a new report by U.N. scientists. trib.al/1Z3wg6Q
Yann LeCun retweeted
I'd like to share a little about what I've been working on at my new company @ultrametricai with my cofounder @tylerlastovich. We have been exploring how we could automate the startup itself, leaving founders with more time to focus on their exact mission.
Enter our first release of the Open Startup Repo: github.com/ultrametricai/ult…
A common foundation for transparent automation of the startup.
After close to 20 years in silicon valley, backing hundreds of amazing founders & startups, being in the trenches of founding Heyzap (YC08), then solo founding @golden, going through 2 acquisitions and working behind the scenes with some of the iconic companies today, I'm witnessing the largest change to how we work I could have imagined - a truly monumental era of creative abundance.
I believe the next generation of companies will largely run themselves: from operations, code, product upgrades, growth, vendor control & selection, process execution, special situations, strategy etc etc. That leaves founder time for 'the art' at the very niche core: the (currently) unautomatable, the special leaps humans tend to make, and north star setting.
We want founders to go super deep into the main problem they are trying to solve and not get held up doing anything else, from searching for domain availability with trademark checks to setting their company up, to running their processes on autopilot.
So to help that broad foundational layer for starting and running a company, we have spent around a year exploring how to help founders focus on their mission across different verticals, geos, stages and initial starting conditions.
Our first few attempts at making something useful actually failed as the market and AI was moving so fast; it just got absorbed into the models or other product releases. We saw polsia happen, openclaw, then grokbot, muse, dots, etc era as the astras, fables, opuses, kimis and jevs rolled out. What seemed to have been missing along the way was a common repo to identify, unify, open and normalize all the lego bricks that startups have to interact with (vendors, processes, business logic, law, best practices, surface areas, art of the possible).
As the number of software vendors blew up, the interfaces to drive them multiplied, the international startup founder blew up as silicon valley moved from a specific location to a state of mind and global movement. Unlimited pre seed funding in unlimited vertical sub markets and permutations has brought us to the age of infinity but we have yet to achieve being able to type into an agent a very simple sentence with very complex implications 'just setup my company and make $1m/m'. We have ended up with a hybrid mismash of computer use, API calls, plugins, shifting surface areas (API/MCP/CLI/plugins/chats/musish futures), and changing model absorption to vendor balance making it an exciting and unstable time.
As our first step we started to rank all the vendors that startups interface to when going about their journey in terms of how agentically controllable they are via their APIs, MCPs, CLIs etc and computer use compatibility as we are largely switching from a UI driven world to the agentic control surfaces and onto full automation. We have 100 ranking areas you can check out with an overall open ranking here: ultrametric.ai/overall
Then we looked at the processes that startups do and how the vendors rank for the sub steps or process as a whole and how this changes across geos. Open processes: ultrametric.ai/processes
Then we started to hack on an open repo for startups that would contain all the components we are going to need for a common foundation for founders across the globe even if our gov processes vary so much from Bengaluru to SF or Lisbon to Shenzhen. The founder spirit is geo-invariant.
We have looked at special founder/startup situations, the business logic that will make open modules for the startup that we can hack on together, ranked law firms, government services and interfaces, stacks that go well together. We have mapped the law and lore that maps to startups and the schemas that make up the data objects and documents. But also the open documents and the missing gaps. MUCH TO DO.
All the BS processes and fluff work that founders waste their time on needs to goto zero. I want to see more supersonic planes, cancer drugs, seemingly impossible missions done and increase the bang for buck founders have with their funding.
This is a work in progress and we are keen for the community to come hack on the repo with us here: github.com/ultrametricai/ult…
Lets get into the structure of the general repo and the visualizations we made on ultrametric.ai site with example links:
- Open rankings: ultrametric.ai/overall
- Open rankings example (online payments): ultrametric.ai/arena/payment…
- Open ranking example 2 (cap table): ultrametric.ai/arena/equity-…
- Open processes: ultrametric.ai/processes
- Open process example (Incorporate C-Corp) ultrametric.ai/processes/inc…
- Open situations that founders face: ultrametric.ai/situations
- Open startup simulator (you can test our different initial starting conditions): ultrametric.ai/startup-sim
- Open modules (e.g. cap table, payroll logic etc - we'd love help improving these) ultrametric.ai/open-modules
- Open law (we are interested in how law changes the processes, situations and normalizing this over time) ultrametric.ai/open-law
- Open lore (we are interested in the historical lore of startups, the rules of thumb and heuristics that might guide your agent): ultrametric.ai/open-lore
- Open fields (we are interested in how the schema for the data connects to the open modules, business logic, open documents and artifacts of each process eg how is a EIN defined?) ultrametric.ai/fields
- Open documentation (eg SAFE notes and missing! docs) ultrametric.ai/open-document…
We have looked at YC companies as well in terms of which ones do well agentically: ultrametric.ai/yc
We are interested in stacks and how people are changing their work: ultrametric.ai/stacks
We are interested in what is automatable and where the agentic ceiling is currently and how to push that up in all areas: ultrametric.ai/rankings/proc…
There is more for you to explore and a lot more coming in terms of how you will be able to navigate business in an optimal way in your chosen surface area; whether you are hanging in grokbot, dots, muse, claude, terminal, chat, or whatever is coming up in this exciting time.
We have a lot of data to collect, clean up and help agents navigate the vast landscape emerging functionality the entire startup ecosystem has to offer.
Come join us getting your vendor in, ranked or that access pattern you have wanted or getting the data more accurate in terms of which vendor is best for a process or steps. Or open a module of something that currently cost money that could be free.
Also come play in our discord for founders and join the chaos (we can solve each others issues including fund raising tips from me personally): discord.com/invite/3aHky836q…
It's time to lift all the boats in the harbor and I'm extremely excited as to what the community of hackers and painters will hack into the repo, what asks they will have and whether we can shift normalization of processes globally, gov agentic interfaces and have common repo for founders that grows over time. I expect a lot of experimentation along the way, bugs and upside...
I appreciate our backers having faith in us as well from @ycombinator with @garrytan to @immad doing a sizable check (congrats on $1bn rev homie) to @darbyw (congrats on Stripe buying @clerkyinc), @drewhouston form @Dropbox and also @pioneer_fund @tomerlondon cto @GustoHQ and hopefully this is 'boring' and complex enough for Charlie Songhurst :> @delingpole @Liquid2V @ivolo from @segment @ryanpowe @sonicaghi of @kong @DellyTamer+ other supporters (@michaelwfrank, Fundamental ventures and if I missed you sorry moving fast!).
[And don't worry, all vendor rankings are open scoring methods so no favors are being done if someone backed us and is a vendor they have to compete with how agentic and automatable they are just like anyone else.]
PS: we have bugs and many quality upgrades to make but thought better to go out early and fix as a community.
PPS: we have other stuff to launch we just thought this was a great place to start and have 200 PRs coming out pretty soon but I still want to know what is broken or doesnt make sense or inaccurate.
Special thanks to current and past team members for getting us here and all the experiments we did you know who you are.
Yann LeCun retweeted
Ukraine was winning the war, so Trump kneecapped Ukraine to help Russia.
I wish it weren’t that simple, but it is. Our president is in bed with our enemies.
Yann LeCun retweeted
ELON FANS WON'T LIKE THIS ONE...
BUT HERE ARE 10 BIG THINGS ELON PROMISED THAT NEVER HAPPENED:
The New York Times went through 15 years of his posts and interviews.
He made 602 promises with a date on them.
Only 1 in 5 happened on time.
Here are some of them:
1. In 2015 he said Teslas would fully drive themselves in 2 or 3 years.
11 years later, you still have to keep your eyes on the road.
2. In 2016 he said a Tesla would drive itself from LA to New York by the end of 2017.
It never did.
3. In 2019 he said there would be 1 million robotaxis by 2020.
Today there's a small service in Austin. With a safety person sitting inside.
4. In 2017 he said the new Tesla Roadster would come out in 2020.
They just showed it this month. Now it's coming in 2028.
5. For years he talked about a cheap $25,000 Tesla.
Then he dropped it and called the idea "pointless."
6. In 2016 he said SpaceX would send a ship to Mars by 2018.
Later he said people would be on Mars by 2024. Nobody has gone. Not even an empty rocket.
7. In 2013 he said Hyperloop would take you from LA to San Francisco in 35 minutes.
What we got is Teslas driving through a tunnel in Las Vegas.
8. When he bought Twitter, he said a team would be set up before any big decisions on banned accounts.
That team never showed up.
9. With DOGE he promised $2 trillion in government cuts.
Studies found it saved almost nothing.
10. He said his AI company would build AI smarter than humans by 2025. Still waiting.
Yes, he's also done crazy things. Rockets that land themselves. Starlink. Making electric cars normal.
But even he admits he only expects to hit his deadlines about half the time.
So today he posted that he'll give one SpaceX share to every kid in America next year.
That's around 73 million kids.
He hasn't said how. Or who gets it. Or who pays the tax.
Save this post. We'll check back in 2028.
Written by: @carlmoon
Yann LeCun retweeted
Pocket TTS has been getting updates those last few days. While it was ~100M parameters, we release smaller versions, down to 1.9M: an 18.2M model with the quality of the original, a 6.9M model, and a 1.9M model that runs 103x faster than real time on one CPU core. All with voice cloning.
Yann LeCun retweeted
It speaks to the unchecked power of the American presidency that a single warped occupant of the Oval Office can transform the United States into an ally of Putin even as most Americans are outraged by his invasion of Ukraine and targeting of civilians. trib.al/86S0yX6
Yann LeCun retweeted
Washington has discovered a brilliant financial strategy. Cut benefits for people who need them, cut taxes for people who don't, and borrow the difference from people who aren't old enough to vote.
Yann LeCun retweeted
Trump has raised $330 million from private donors for his White House ballroom.
About half have received federal contracts during his second term, according to The Washington Post.
Here are the top 16 givers.
Yann LeCun retweeted
I'm definitely not anti-achievement and never criticized real achievements, including by Elon.
I even own two Teslas.
I do expose marketing stunts that, while cool on the surface, are not the achievements they are claimed to be.
Compressed air thrusters might give you acceleration boosts in any direction.
They might even make your car hover for a couple of seconds if you accept replacing the passenger seat by a 400 liter high-pressure air tank.
But they are not a path to actual flying cars.
The same way Burt Rutan's SpaceshipOne was never going to be a path to orbital flights (just bunny hops out of the atmosphere).
I am anti-Musk when it comes to politics. His political actions, the massive dissemination of disinformation through X and other channels, and his support for authoritarian regimes and racist ideas have the effect of weakening democracy and weakening human decency and social progress around the world.
Yann LeCun retweeted
Everything Yann said here is roughly correct, and Musk knows it, which is why he responded like a 14-year-old.
Calling @MKBHD’s video “hate” is misguided and highlights the nearly insurmountable issue the Tesla community has with criticism.
There was plenty to criticize about that unveiling and I thought Marques did an incredible job.
He is becoming a great force pushing against the growing movement in tech and now automotive of over promising and under delivering.
Yann LeCun retweeted
Yann LeCun, one of the world’s foremost AI, machine-learning and robotics researchers, an engineer, NYU professor and ACM Turing Award laureate, has been torn to pieces today by Elon Musk fans for daring to inject some reality into the Tesla Roadster debate.
The objection isn’t that the technology isn’t impressive. It is how these capabilities are being marketed, with deposits being taken on the basis of what we’ve been shown.
The physics remain the problem. A production car carrying enough compressed air to deliver those levels of thrust would face enormous compromises in weight, storage capacity and recharge requirements. At best, you’re looking at seconds of extreme thrust, followed by specialist recharging that can absolutely not be integrated into the car - literally impossible because of the weighty equipment needed & the energy required for that equipment to compress 600L of air for a few seconds of thrust.
And let’s not forget that the Roadster 2.0 was announced in 2017. Nine years later, instead of finally putting that car on the road, we’re watching a new version of the same old story.
This isn’t hate. It’s realism based on experience, engineering and physics.
And when someone like @ylecun makes essentially the same observations, the response shouldn’t be “What have you ever achieved?” or "what do you know?" - sure, use that one on me, but not on Yann.
I'm definitely not anti-achievement and never criticized real achievements, including by Elon.
I even own two Teslas.
I do expose marketing stunts that, while cool on the surface, are not the achievements they are claimed to be.
Compressed air thrusters might give you acceleration boosts in any direction.
They might even make your car hover for a couple of seconds if you accept replacing the passenger seat by a 400 liter high-pressure air tank.
But they are not a path to actual flying cars.
The same way Burt Rutan's SpaceshipOne was never going to be a path to orbital flights (just bunny hops out of the atmosphere).
I am anti-Musk when it comes to politics. His political actions, the massive dissemination of disinformation through X and other channels, and his support for authoritarian regimes and racist ideas have the effect of weakening democracy and weakening human decency and social progress around the world.
Yann LeCun retweeted
Trump’s longstanding groundless attacks on the integrity of voting systems are crystallizing into what many fear is an attempt to lay the groundwork to challenge the results in November when Republicans are expected to lose big time. trib.al/nTtaiY2
Yann LeCun retweeted
People seem confused about why Tesla is getting so much backlash over its new "flying Roadster." For those of us who were once genuinely enthusiastic about Tesla, this isn't about hating innovation. It's about a long history of broken promises, misleading expectations, and increasingly absurd marketing.
Tesla unveiled the second-generation Roadster in 2017, took customer deposits, and promised deliveries in 2020. Six years past that deadline, it still hasn't delivered the car. Instead, it's demonstrating an even more outrageous version with features that will likely never make it into production. The original 2nd gen Roadster would still be an amazing car today. Why not just deliver what was promised?
Then there's Full Self-Driving. Tesla marketed the idea that Model 3 owners could turn their cars into income-generating robotaxis. That never materialized. Even if the technology eventually gets there, the opportunity has already passed for many early buyers. Timing matters. Delivering something a decade late isn't fulfilling the promise you sold to customers.
And then there's Solar Roof. Unveiled in 2016 as a revolutionary approach to residential solar, it struggled with costs, installation challenges, and adoption far below expectations. After nearly a decade, Tesla discontinued it entirely in August 2026. Another grand vision abandoned, leaving existing customers with a discontinued product to maintain.
Then came the Cybertruck, marketed as a nearly indestructible, revolutionary truck. Instead, we got a vehicle with questionable build quality, numerous recalls, expensive repairs, disappointing results in several real-world off-road tests, and specifications that fell short of the original promises. It literally looks like a dumpster, but aesthetics aside, the collapsing demand speaks volumes about the reality of what Tesla delivered. Another heavily hyped product that fell dramatically short of expectations.
This is how consumer trust erodes. Not through one disappointment, but through years of accumulating them. And this is part of the reason why many people who were once enthusiastic about Tesla have become critical and cynical about it.
But there's something even more fundamental here: Tesla has completely departed from the grounded, practical vision that made so many of us enthusiastic about the company in the first place.
Electric cars were ambitious, but the idea was grounded in reality. People could charge at home, infrastructure could gradually expand, technology could improve, and millions of ordinary people could eventually benefit. There was a realistic path toward mass adoption.
What the hell does a flying Roadster powered by compressed-air thrusters have to do with any of that?
It's an expensive, impractical engineering stunt with enormous packaging, safety, and regulatory challenges, and no credible near-term path toward mass-market usefulness. Modern electric cars already achieve ridiculous acceleration without this nonsense. What practical problem does it solve? Who actually needs it? When will ordinary consumers benefit?
And watching Tesla fans compare this experimental prototype in a Roadster-shaped shell to actual production vehicles people can buy today is ridiculous.
What's especially infuriating is the cult-like mentality surrounding all of this. You can't point out the history of failed promises, question the practicality, or demand realistic timelines without being accused of being a "hater" or having "Elon derangement syndrome."
Tesla deserves recognition for helping make electric cars a reality, but that success doesn't give it a blank check to keep marketing increasingly fantastical promises while failing to deliver on previous commitments.
This isn't hatred. It's disappointment from people who once believed in the company, watched it accomplish extraordinary things, and have since watched it increasingly substitute practical innovation with spectacle and promises.
Elon fanboys are also ignoring a bigger pattern that goes beyond Tesla.
What made many of us enthusiastic about Elon and Tesla and in the first place was a grounded vision of technological progress that could genuinely improve millions of lives. Electric cars were ambitious, but practical, achievable, and useful to ordinary people. Now we're supposed to get excited about flying cars with compressed-air thrusters that have no credible path to mass adoption and solve no meaningful problem for the average consumer.
It's the same kind of thinking behind marketing the colonization of Mars as some urgent necessity for humanity's survival. There's nothing wrong with space exploration, but Earth isn't about to become uninhabitable because of the Sun. We're talking about geological timescales, while humanity faces enormous problems RIGHT NOW: poverty, hunger, access to education, corruption, abuse of power, wars, and a lack of government accountability. We have plenty of very real problems to solve before worrying about humanity's survival on another planet.
And then there's DOGE. I was genuinely excited about the original idea of making government more efficient, reducing waste, and increasing accountability. Instead, we got questionable savings figures, inexperienced people making sweeping decisions, serious concerns over access to sensitive personal information, and an initiative that ultimately fizzled out without delivering its grand promises. Another enormous narrative that fell apart when confronted with reality.
That's what makes all of this so frustrating. It's not that we stopped believing in technological progress. It's that we've watched someone who once pursued grounded, transformative ideas increasingly embrace fantastical promises, political spectacle, and questionable narratives disconnected from practical reality.
And somehow, pointing out this history of disappointment gets you labeled a "hater" or accused of having "Elon derangement syndrome."
The problem isn't dreaming big. It's repeatedly selling people those dreams, failing to deliver, and then expecting everyone to applaud the next, even more ridiculous promise without asking what happened to the last one.
The world doesn't need more spectacular promises. It needs practical solutions to real problems, honest expectations, and accountability for what was promised. That's what made Tesla exciting in the first place, and that's what so many of us feel has been betrayed.
Yann LeCun retweeted
Trump’s approval rating has dropped in every religious group since the beginning of his second term.
Today, White evangelical Protestants are the only religious group in which more people approve than disapprove of Trump’s job performance (58% vs. 40%).
ALT Chart showing Trump’s approval rating from every religious group is lower now than at the beginning of his second term
ALT Chart showing that in nearly all religious groups, more people disapprove than approve of Trump’s job performance
Yann LeCun retweeted
Okay, so it's just compressed air.
Easier.
But crappy specific impulse (less than 50 seconds).
Even assuming that 50% of the mass of the car is the compressed air, that gives you less than 10s of useful thrust (with thrust-to-weight ratio larger than 1.0). Probably more like 5 seconds, actually.
So the car must be an empty, lightweight shell containing big compressed air tanks.
Cute demo, but totally impractical.
But of course, you knew that.
Yann LeCun retweeted
My new investigation maps nearly $3 BILLION in historical and projected funding behind the AI existential-risk ecosystem.
Yann LeCun retweeted
“At a time when Donald Trump’s party is struggling to hold both houses of Congress and his own approval ratings are cratering to historic lows, the President has been campaigning hard all week against . . . Volodymyr Zelensky,” Susan B. Glasser writes. “Yes, Trump’s October preëlection surprise is that he’s finally decided to begin openly helping Vladimir Putin in Russia’s war of conquest against Ukraine.”
“Trump has pivoted to Putin so many times before that it should hardly astonish anyone that he did it again,” Glasser continues. “But these crises that Trump provokes with such regularity always manage to reveal something new, and this one has been no exception, showing a President so politically cornered by the consequences of his war in the Middle East that he turned to Putin to help him out with less than three weeks to go before the midterm elections.” Read her latest column: newyorkermag.visitlink.me/y7…
Yann LeCun retweeted
Trump says drug prices are down 300–700% and Americans pay “the lowest drug prices” in the world.
Prescription drug prices are down only 3.9%, and our prices are still near the top of the list.
My @Morning_Joe Chart
