Kyle Kosic

@Yuhu_ai_ 🫡

I resigned from xAI today. This company - and the family we became - will stay with me forever. I will deeply miss the people, the warrooms, and all those battles we have fought together. It's time for my next chapter. It is an era with full possibilities: a small team armed with AIs can move mountains and redefine what's possible. Thank you to the entire xAI family. Onward. 🚀 And to Elon @elonmusk - thank you for believing in the mission and for the ride of a lifetime.

@davidtolnay OpenAI Codex TUI was released on April 16th

For the past 3 months I have been watching a surprising instantaneous discontinuity in the adoption pattern of many widely used Rust libraries. See for yourself in the attached graphs, which show the fraction of crates‑io with a direct dependency on each of these crates. The inflection in April 2025 is not subtle. These crates are suddenly massively more widely used in new code than they used to be, including crates that have been previously on an extremely consistent trajectory for a half decade, like base64 and thiserror. I spend a lot of time examining graphs like this to make sense of the ecosystem and I noticed this emerging a while ago. I can say it is unprecedented in the history of crates‑io for usage patterns to shift drastically like this in a broad spectrum of crates. My best guess is that AI uses these crates at a different rate than the human authored baseline rate, and crates‑io is currently being inundated with AI-authored code. Can someone help line this up with a product launch?

We shape our codebases and afterward our codebases shape us

@ibab Good luck, and many thanks for putting together a great engineering team and the most enriching experience yet of my life!

Today was my last day at xAI, the company that I helped start with Elon Musk in 2023. I still remember the day I first met Elon, we talked for hours about AI and what the future might hold. We both felt that a new AI company with a different kind of mission was needed. Building AI that advances humanity has been my lifelong dream. My parents left the Russian Federation after the collapse of the USSR in search of a better life for their kids. Life wasn’t always easy as immigrants. Despite the hardships, my parents believed that human values were priceless: values like courage, compassion, curiosity for understanding the world. As a child, I admired scientists like Richard Feynman and Max Planck, who relentlessly pushed the frontiers of physics in order to understand the universe. As a particle physics PhD student at CERN I was excited to contribute to that mission. But the search for new physics was getting harder and harder, requiring bigger and bigger colliders, while new discoveries kept getting fewer. So I began to wonder if superintelligence, not larger colliders, could be the key to unlocking the mysteries of the universe. Could AI develop a consistent theory of quantum gravity? Could AI prove the Riemann hypothesis? In early 2023 I became convinced that we were getting close to a recipe for superintelligence. I saw the writing on the wall: very soon AI could reason beyond the level of humans. How could we ensure that this technology is used for good? Elon had warned of the dangers of powerful AI for years. Elon and I realized that we had a shared vision of AI used to benefit humanity, thus we recruited more like minded engineers and set off to build xAI. The early days of xAI were not easy. Naysayers told us that we arrived too late to the game, so starting a top AI company from scratch would be impossible. But we believed we could do the impossible. Starting a company from zero required lots of hands-on work. In the beginning I built many of the foundational tools used at the company to launch and manage training jobs. I later oversaw much of the engineering at the company, including Infrastructure, Product and Applied AI projects. xAI’s people are deeply dedicated. Through blood sweat and tears, our team’s blistering velocity built the Memphis supercluster, and shipped frontier models faster than any company in history. I learned 2 priceless lessons from Elon: #1 be fearless in rolling up your sleeves to personally dig into technical problems, #2 have a maniacal sense of urgency. xAI executes at ludicrous speed. Industry veterans told us that building the Memphis supercluster in 120 days would be impossible. But we believed we could do the impossible. Our goal was to get our training setup running at scale on the Memphis cluster ASAP. Towards the end of our 120 day deadline, we were riddled with mysterious issues with communicating over RDMA between the machines. Elon decided to fly to the datacenter, and we followed. Our infra team landed in Memphis in the middle of the night and got straight to work. After pouring through tens of thousands of lines of lspci output we finally identified a wrong BIOS setting, the root of the problem. Elon was there with us until late into the night. When the training run finally worked, Elon posted our triumph at “4:20am” causing us to laugh out loud. I will never forget the rush of adrenaline that night, and the emotional bonds that we were all in this together. We went to bed feeling like we were living through the most exhilarating time of our lives. I have enormous love for the whole family at xAI. Our team is truly special - you’re the most dedicated people I’ve ever worked with. Catching up to the frontier this quickly hasn’t been easy. It was made possible by everyone’s diehard grit and team spirit. Thank you to every single person who joined me on this adventure. I want to honor your contributions, your time, your sacrifices, which are never easy. I will always remember working together far into the nights and burning the midnight oil. I will never forget the sacrifices and contributions you’ve made. As I drive away today, I feel like a proud parent, driving away after sending their kid away to college. My heart is brimming with tears of joy, rooting for the company as it grows and matures. As I'm heading towards my next chapter, I’m inspired by how my parents immigrated to seek a better world for their children. Recently I had dinner with Max Tegmark, founder of the Future of Life Institute. He showed me a photo of his young sons, and asked me “how can we build AI safely to ensure that our children can flourish?” I was deeply moved by his question. Earlier in my career, I was a technical lead for DeepMind's Alphastar StarCraft agent, and I got to see how powerful reinforcement learning is when scaled up. As frontier models become more agentic over longer horizons and a wider range of tasks, they will take on more and more powerful capabilities, which will make it critical to study and advance AI safety. I want to continue on my mission to bring about AI that’s safe and beneficial to humanity. I’m announcing the launch of Babuschkin Ventures, which supports AI safety research and backs startups in AI and agentic systems that advance humanity and unlock the mysteries of our universe. Please reach out at ventures@babuschk.in if you want to chat. The singularity is near, but humanity’s future is bright!

That men do not learn very much from the lessons of history is the most important of the lessons that history has to teach us. – Aldous Huxley

GPT5 is substantially better at coding imo – first model I've used that seems competent at Rust

We released two open-weight reasoning models—gpt-oss-120b and gpt-oss-20b—under an Apache 2.0 license. Developed with open-source community feedback, these models deliver meaningful advancements in both reasoning capabilities & safety. openai.com/index/introduc…

a=(x,y,d=mag(k=(4+sin(x/11+t*8))*cos(x/14),e=y/8-19)+sin(y/9+t*2))=>point((q=2*sin(k*2)+sin(y/17)*k*(9+2*sin(y-d*3)))+50*cos(c=d*d/49-t)+200,q*sin(c)+d*39-440) t=0,draw=$=>{t||createCanvas(w=400,w);background(9).stroke(w,96);for(t+=PI/240,i=1e4;i--;)a(i,i/235)}#つぶやきProcessing

@Guodzh Very impressive work, great job!

We were barely able to train at 10k early last year, but we got 100k training non-stop for Grok3. So proud, more to come!

Little things like this quickly add up to a huge productivity boost. I needed a quick linux sandbox for Rust development – an hour of likely trial and error took 2 minutes: chatgpt.com/share/97746695…

@xanderai github.com/kykosic/dotfil…

@kylekosic Have you upgraded vim -> neovim and moved init.vim -> config.lua? It was a really nice improvement for me: github.com/xanderdunn/bas…

Fixing the annoyances of your vim config are an important form of self care.

@xanderai Yes I have! I'll have to make my dotfiles public at some point

My hobby: Going into SF coffee shops and playing the PagerDuty alert.

@karpathy Couldn't agree more. If you can afford to do so, make sure you occasionally unplug for a week and read some classics.

Returning from an experimental ~2 week detox from the internet. Main takeaway is that I didn't realize how unsettled the mind can get when over-stimulating on problems/information (like a stirred liquid), and ~2 weeks is enough to settle into a lot more zen state. I'm struck by how an over-stimulated brain automatically keeps bubbling up problems into consciousness, creating a state of persistent anxiety and nervousness. After some time, in the settled state, this activity just... stops. You can sit down and your brain doesn't immediately go into some kind of problem solving overdrive, it just stays silent. Nothing happens. I'm sure this could read a bit duh to many, but I haven't been to this subset of "brain dynamics" state space in I think a very long time and it is comforting to know that 1) it exists, and 2) you can visit, if you like, but the journey there takes a few weeks. Anyway, where were we :D

@elonmusk #StopHomousianHate

History is complicated en.m.wikipedia.org/wiki/First_Cou…

@gdb First solve AGI, then bluetooth pairing

if you don't know how to solve a problem, start by solving a lesser version of it

@obsdmd is the first software in ages I've been really excited to use. Reminds me of my early coding days being introduced to Sublime Text. Great product.

@sama idk there have been some pretty wild years

this is the most interesting year in human history, except for all future years

"It matters very little whether your judgments of people are true or untrue, and very much whether they are kind or unkind." – Winston Churchill