Aditya Prerepa
686 posts
I left xAI earlier this year after two incredible years.
I joined still early in my career, and had the privilege of meeting many great people and friends along the way. Over time, I ended up leading pretraining across architecture, training, and parts of infra, and later led major RL runs for Coding. Together, we pushed forward generation after generation without missing a beat. None of this would have been possible without the fantastic team.
Grateful for my team and friends —their talent and dedication made this possible. Working through hard problems together was the most rewarding part of the journey, and I’ll miss it deeply.
It’s hard to walk away from people you’ve spent years building with. But I’m proud of everything we built together, and ready for the next chapter.
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@HeinrichKuttler whew !! palo alto roads just got safer, i was getting worried 😅
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Finally doing my CA driver license. Guess:
When is it permitted to drive across double solid yellow lines?
A When making a U-turn or left turn.
B When the road is clear to pass the vehicle in front of you.
C When instructed by construction or other signs due to a road closure.
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Incredibly proud the xAI team's execution in bringing on an immense amount of compute so quickly & couldn't be more excited for Elon's vision of an abundant future w/ intelligence spreading to the stars
Over the past weeks I've had the pleasure of getting to know the team at Anthropic & share similar vision - I'm happy to announce I'm joining the team there to focus on compute
Onward towards building a future we're all excited about
xAI@xai
SpaceXAI will provide @AnthropicAI with access to Colossus 1, one of the world’s largest and fastest-deployed AI supercomputers, to provide additional capacity for Claude → x.ai/news/anthropic…
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Career update: I resigned from the inference team at @xai and joined @radixark last month.
Excited to build open and efficient AI infra — making frontier-grade training & serving accessible to everyone. The SGLang/Miles momentum is unreal, and the team is shipping fast. 🚀
RadixArk@radixark
Today, we are thrilled to officially launch RadixArk with $100M in Seed funding at a $400M valuation. The round was led by @Accel and co-led by @sparkcapital. RadixArk exists to make frontier AI infrastructure open and accessible to everyone. Today, the systems behind the most capable AI models are concentrated in a small number of companies. As a result, most AI teams are forced to rebuild training and inference stacks from scratch, duplicating the same infrastructure work instead of focusing on new models, products, and ideas. RadixArk was founded to change that. We are building an AI platform that makes it easier for teams to train and serve the best models at scale. RadixArk comes from the open-source community. We started with SGLang, where many of us are core developers and maintainers, and expanded our work to Miles for large-scale RL and post-training. We will continue contributing to both projects and working with the community to make them the strongest open-source infrastructure foundations for frontier AI. We would like to thank our long-term partners, contributors, and the broader SGLang community for believing in this mission. We're also grateful to @Accel and @sparkcapital, NVentures (Venture capital arm of @nvidia), Salience Capital, A&E Investment, @HOFCapital, @walden_catalyst, @AMD, LDVP, WTT Fubon Family, @MediaTek, Vocal Ventures, @Sky9Capital and our angel investors @ibab, @LipBuTan1, Hock Tan, @johnschulman2, @soumithchintala, @lilianweng, @oliveur, @Thom_Wolf, @LiamFedus, @robertnishihara, @ericzelikman, @OfficialLoganK, and @multiply_matrix among others. Thanks for the exclusive interview with @MeghanBobrowsky at @WSJ about our vision.
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@JackCaiXun bye goat
gonna miss the unmoderated multimodal endpoints 😢
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I resigned from xAI yesterday. But I still dreamt about it whenever I take a nap, no matter finished work, ongoing, or something I wanted to do but didn’t have chance to. An unforgettable experience like this can rewire your brain and gives you a chill whenever you think about it.
I worked with a lot of brilliant minds at xAI, not just within Grok Imagine, and I want to thank you all for making it like a family to me. Thanks Elon, you built this platform where miracles happened. I will miss xAI, but I’m sure the world outside is just as exciting, and I can’t wait to take on this journey.
Lastly, I want to thank my wife for her endless support. Last year, I hopped on an airplane to SF not knowing what was coming to me. Her support helped me to go through the toughest time, and I can’t wait to reunite with her again!
— sent from anonymous flight
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After 1 year at @xai, I'm joining @periodiclabs to build the RL system for atoms.
xAI was a once-in-a-lifetime experience: building the inference stack at megascale from zero, countless late-night debugging sessions, endless memes and Slackmojis with the team. I'm deeply grateful for the trust xAI leaders (@lm_zheng @ying11231 @Guodzh @makro_ai) placed in me, and for the incredible people I got to build alongside. AGI really is the friends we made along the way.
Digital AI has come incredibly far, and I have no doubt physical AI will go through the same revolution, starting from the fundamentals: atoms and labs. Born and raised in Taiwan, I deeply understand how transformative materials are to technology — and how much is still left to explore.
Periodic Labs has an unmatched combination of elite scientists and research engineers, tackling one of the most ambitious problems out there. I'll be focused on building the world's first and best RL system for atoms. So excited to work with @LiamFedus @ekindogus @AnjneyMidha to build a better future for humanity!
Bonus: we'll be building on a lot of open source technology and contributing back generously — feels incredible to be back in the OSS community again.
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PD disaggregation… on a single node?
@AMD and @EmbeddedLLM just dropped a blog post on the MORI-IO KV Connector and it’s giving vLLM 2.5× higher goodput.
Perfect intro to PD disaggregation, explains the fundamentals with real single-node results.
Stable buttery decode even at max load 🔥
This is huge for single-box inference.
Full blog + benchmarks + code:
vllm.ai/blog/moriio-kv…
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is this guy for real? I am not surprised he has 11% MFU
I already pay for X premium+, if you can't even give me free trial of your new Groktarded AI, enjoy leading the company with the highest GPU-to-IQ ratio
Tech Dev Notes@techdevnotes
Grok 4.3 can create PDF and almost any file formats like Sheets, Slides, Doc
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Update on the below: 9 months later we're expecting our third child any day now.
I decided to focus on my family for a while. Leading Supercomputing at @xai will remain the honor of my life. Thank you @elonmusk for the opportunity. We will win.
heiner@HeinrichKuttler
me trying for kid no. 3:
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Georgia Tech is a good trade school but it isn't known for producing highly productive or creative people
The most famous founder from there in recent years was the Soylent guy, and he got ousted because there were rats in production facility
altra@catboosted
Just a reminder, if anyone says they went to Georgia Tech for grad school, 99% of the time they did the online degree which basically lets in everyone
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