Behrooz Ghorbani @_ghorbani
Leading Reinforcement Learning at @Reflection_ai. Scaling RL for frontier reasoning models. Formerly @OpenAI, @GoogleBrain and @stanford_ee. web.stanford.edu/~ghorbani/ San Francisco, CA Joined December 2017-
Tweets162
-
Followers2K
-
Following637
-
Likes1K
Huge congratulations to @bneyshabur, @HarshMeh1a, @shayan_, and @tararezaeikh on launching @mirendil! AI for science is one of the most important frontiers, and I can’t wait to see this exceptional team accelerate discovery.
Today, I’m excited to formally announce @mirendil with my amazing co-founders Harsh Mehta, Shayan Salehian, and Tara Rezaei! We’re fortunate to work with @a16z and @kleinerperkins, who led our seed round of $200M, followed by a major investment from NVIDIA, among others.
I’m joining the OSS team at @reflection_ai! 🙏 My life mission has always been to work on open intelligence but there was always a missing piece in my skills: PyTorch taught me the magic of combining Infra knowledge with applied research @joespeez allowed me to be the dumbest person in the room and I learned more from him in those months than all years of my career. It was a total intern feeling and was the happiest I’ve felt in a while. I was convinced that working on OSS infra and applied research should be my next chapter. I’m very grateful to @MishaLaskin and @real_ioannis to allowing me to be a part of the dream To stronger chai and greater learnings at the frontier!
Exciting times at @reflection_ai! Science moves faster when researchers can inspect, adapt, reproduce, and build. That is why open models matter. If you want to build models that move science forward, come join us.
Our open models are designed to support the Genesis Mission by giving the scientists in our national labs the flexibility and sovereignty to work on their own terms. Learn more ⤵️
Culture is a moat
AGI is in its first stages of take-off. Every country is realizing that AI sovereignty is existential, which requires open models. We’ve signed a deal with Shinsegae Group to build South Korea’s sovereign cloud on a US open model built by Reflection. More to come.
Proud to share that Reflection is partnering with Shinsegae Group to build a 250MW AI factory for Korea’s sovereign AI 🇰🇷 Excited to keep pushing the frontiers of RL, reasoning, and open models with this team! wsj.com/tech/ai/nvidia…
Excited to announce that, after finishing my PhD a couple of months ago, I will continue to do *open* science at @reflection_ai on @_ghorbani's new team! And we are still looking for exceptional individuals to join us 😉
Hi friends, after three incredible years at OpenAI I am excited to share that I am starting a new chapter at @reflection_ai, where I will be leading the Science of Scaling team. Our mission is to deepen the scientific understanding of large scale learning and to turn compute
@psanfernandes @reflection_ai Welcome to the team Patrick! Excited to work together 🔥🔥🔥
Most approaches to “agentic AI” focus on post-training fixes. In this conversation, member of our technical staff, @achowdhery argues the bottleneck is pre-training itself. Drawing on her work on PaLM and early Gemini, she explains why next-token prediction breaks down for long-horizon planning -- and how objectives, attention, and training data must evolve to support true agentic behavior.
Today, we're joined by @achowdhery, member of technical staff at @reflection_ai, to explore the fundamental shifts required to build true agentic AI. While the industry has largely focused on post-training techniques to improve reasoning, Aakanksha draws on her experience leading
I am deeply grateful to my colleagues at OpenAI. It has been a privilege to be there from the early days of ChatGPT and to learn from so many brilliant people, especially the reasoning team, which has been my home these past few years and a constant source of insight, collaboration, and support. Thank you for everything we built together. I am excited for what comes next.
In Science of Scaling we will focus on three pillars: understanding LLM training dynamics at scale, the role of real and synthetic data, and the science of RL. I am especially excited to pursue this mission together with @MishaLaskin and @real_ioannis at Reflection. I am building a small, high trust team that cares deeply about open research, careful measurement, and engineering excellence. If you are interested in the science of pretraining, data, and RL at scale and want to help push the frontier with a focused, tight knit group, my DMs are open. I will also be at NeurIPS this week (calendly.com/b-ghorbani-bg/…).
Hi friends, after three incredible years at OpenAI I am excited to share that I am starting a new chapter at @reflection_ai, where I will be leading the Science of Scaling team. Our mission is to deepen the scientific understanding of large scale learning and to turn compute into intelligence as efficiently and predictably as possible.
@appliedcompute Congrats @ypatil125 and team!
Generalists are useful, but it’s not enough to be smart. Advances come from specialists, whether human or machine. To have an edge, agents need specific expertise, within specific companies, built on models trained on specific data. We call this Specific Intelligence. It's what we're building at Applied Compute. We unlock the latent knowledge inside a company, use it to train custom models, and deploy an in-house agent workforce that reports to your team. We work with sophisticated companies that have already captured early gains from general models, like @cognition, @DoorDash, and @mercor_ai. They’re pulling even further ahead with proprietary in-house agents that don’t need to wait for the next public model release. Together, we are building and validating models and agents in days instead of months, achieving state-of-the-art performance on customer evals. Our team has high density and low latency. Our founders all worked on different parts of this problem while they were researchers at OpenAI — @ypatil125 as a key member on the agentic software engineer effort (Codex), @rhythmrg as a core contributor to the first RL-trained reasoning model (o1), and @lindensli as a core contributor on ML systems and infrastructure for RL training. Two-thirds of the team are former founders, and everyone brings a deep technical background, from top AI researchers to Math Olympiad winners. We are backed by $80M in funding from Benchmark, Sequoia, Lux, Elad Gil, Victor Lazarte, Omri Casspi, and others. With their support, we are growing the team, scaling deployments, and bringing to market the first generation of agent workforces built on specific models. In short: 1. We are building Specific Intelligence for specific work at specific companies. 2. That will power in-house agent workforces to support their human bosses. 3. That in turn will unlock AI’s full potential through humanity’s greatest engine of progress: thriving corporations in a free market.
Understanding the capabilities of AI models is important to me. To forecast how AI models might affect labor, we need methods to measure their real-world work abilities. That’s why we created GDPval.
Today we’re introducing GDPval, a new evaluation that measures AI on real-world, economically valuable tasks. Evals ground progress in evidence instead of speculation and help track how AI improves at the kind of work that matters most. openai.com/index/gdpval-v0
the distance between category leaders and stragglers in frontier AI starts with talent and culture by the time the revenue and valuation signals show up, it’s too late
🚀 We’re hiring at NVIDIA! Our team is pushing the frontier of LLM / DLM post-training and system optimization. We are looking for exceptional people with large-scale LLM + systems experience to join us (full time only). 🔹 Focus areas include: •Post-training of large models •Systems for LLM/DLM training & inference at scale •Efficiency, scaling, and evaluation frameworks of LLMs At NVIDIA, you’ll work with world-class researchers and engineers on cutting-edge foundation models at unprecedented scale. 👉 If you’re passionate about LLMs, systems, and building the next generation of AI, we’d love to hear from you. 📩 If you’re interested, please send me your CV! @nvidia #LLM #AI #Systems #PostTraining #DeepLearning
In era of pretraining, what mattered was internet text. You'd primarily want a large, diverse, high quality collection of internet documents to learn from. In era of supervised finetuning, it was conversations. Contract workers are hired to create answers for questions, a bit like what you'd see on Stack Overflow / Quora, or etc., but geared towards LLM use cases. Neither of the two above are going away (imo), but in this era of reinforcement learning, it is now environments. Unlike the above, they give the LLM an opportunity to actually interact - take actions, see outcomes, etc. This means you can hope to do a lot better than statistical expert imitation. And they can be used both for model training and evaluation. But just like before, the core problem now is needing a large, diverse, high quality set of environments, as exercises for the LLM to practice against. In some ways, I'm reminded of OpenAI's very first project (gym), which was exactly a framework hoping to build a large collection of environments in the same schema, but this was way before LLMs. So the environments were simple academic control tasks of the time, like cartpole, ATARI, etc. The @PrimeIntellect environments hub (and the `verifiers` repo on GitHub) builds the modernized version specifically targeting LLMs, and it's a great effort/idea. I pitched that someone build something like it earlier this year: x.com/karpathy/statu… Environments have the property that once the skeleton of the framework is in place, in principle the community / industry can parallelize across many different domains, which is exciting. Final thought - personally and long-term, I am bullish on environments and agentic interactions but I am bearish on reinforcement learning specifically. I think that reward functions are super sus, and I think humans don't use RL to learn (maybe they do for some motor tasks etc, but not intellectual problem solving tasks). Humans use different learning paradigms that are significantly more powerful and sample efficient and that haven't been properly invented and scaled yet, though early sketches and ideas exist (as just one example, the idea of "system prompt learning", moving the update to tokens/contexts not weights and optionally distilling to weights as a separate process a bit like sleep does).
Introducing the Environments Hub RL environments are the key bottleneck to the next wave of AI progress, but big labs are locking them down We built a community platform for crowdsourcing open environments, so anyone can contribute to open-source AGI
LIVE5TREAM THURSDAY 10AM PT
Behnam Neyshabur @bneyshabur
44K Followers 1K Following Co-Founder & CEO @mirendil 💼 Past: co-led Discovery team @AnthropicAI & Blueshift team @GoogleDeepMind 🎒Traveling & Backpacking
Zhimei Ren @RenZhimei
1K Followers 320 Following Assistant professor @Wharton stats. Former postdoc @UChicago & PhD from @Stanford.
Sebastien Bubeck @SebastienBubeck
78K Followers 1K Following I work on AI at OpenAI. Former VP AI and Distinguished Scientist at Microsoft.
Hanie Sedghi @HanieSedghi
7K Followers 1K Following Staff Research Scientist at Google DeepMind. Interested in the science of deep learning. Current focus: Pushing boundaries of LLMs capabilities
Jason Lee @jasondeanlee
37K Followers 5K Following Associate Professor CS/stats UC Berkeley. Former Research Scientist at Google DeepMind. ML/AI Researcher working on LLMs and deep learning. PhD at Stanford.
Sara Hooker @sarahookr
63K Followers 11K Following Building intelligence that evolves @adaption_ai. Built @Cohere_Labs, @GoogleBrain, @GoogleDeepmind. ML Efficiency, Multimodal\lingual.
Ofir Press @OfirPress
19K Followers 9K Following I push the AI frontier by building tough benchmarks with amazing people. SWE-bench, SWE-agent, SciCode, AlgoTune. Postdoc @Princeton. PhD @nlpnoah @UW.
Ari Morcos @arimorcos
7K Followers 2K Following CEO and Co-founder @datologyai working to make it easy for anyone to make the most of their data. Former: RS @AIatMeta (FAIR), RS @DeepMind, PhD @PiN_Harvard.
Weijie Su @weijie444
13K Followers 499 Following Researcher @OpenAI, Professor @Wharton, CS, Math @Penn, coDir PRiML, PhD @Stanford
Ollie Liu @olliezliu
680 Followers 512 Following oliver irl, post-training @reflection_ai prev. @AIatMeta, @CSatUSC, @mldcmu decision making ∩ generative models ∩ ai4sci
Jordan Segall @jordan_segall
2K Followers 1K Following Partner at Redpoint Ventures | Stanford University | Formerly Palantir, RelateIQ, McKinsey, C3, StartX Mentorship Director
Cyrus @cyrusnewday
5K Followers 4K Following Jhanas & AI. Cofounder @SynthesisCoCA (YC S24) | Past @DSPyOSS @NousResearch @WomboAI @UWaterloo SYDE
Charvi Bannur @BannurCharvi
3 Followers 64 Following We're drowning in information and starving for knowledge.
xÖręV @xorevsu2
0 Followers 618 Following
Glenn Gertler @GlennGert
5 Followers 634 Following Talent @ Riviera (acquired Lateral) | AI Recruiter | Past: Harvey, Meta, Amazon
puppyoo @puppyoov1c
2 Followers 72 Following
Lake Mary @Lakemary00
2 Followers 107 Following 🇺🇸 Living life, chasing dreams, and making every day count. ✨
Pierre R @pierrerx
119 Followers 353 Following
Gavin Zhang @GavinZJL
160 Followers 833 Following Research scientist at Meta Superintelligence Labs. Working on training algorithms. PhD @ UIUC. Previously @Stanford and @HarveyMudd.
Moon @Moon189267
6 Followers 22 Following
Juarez de Queiroz Cam... @Juarez_Q_Campos
22 Followers 2K Following Lawyer, PHD Philosophy UFRJ - (EX-CEO https://t.co/TsI3kdtSlP) - (Strategy/AI)
John Murzaku @jmurzaku
455 Followers 389 Following Coding Agents @SnorkelAI. Prev: Evals @adobe, PhD @stonybrooku
t@j @tj08346309
0 Followers 39 Following
Andy Binkley @jandybin
14 Followers 181 Following
Kristopher Norris, CP... @knntwit
286 Followers 1K Following #CPA | #Finance | #BusinessAnalytics | #DataAnalytics | #DataScience | #AI | #Investing | #Technology | #Robotics | #Innovation | #Space | #Fintech | #Biotech
Eric Kaplan @eric_kaplan_nyc
425 Followers 2K Following Investor at @BessemerVP | Previously growth & product @ridewithvia | Seinfeld enthusiast
"Leigh Marie" Braswel... @LM_Braswell
21K Followers 5K Following partner @kleinerperkins; previously investing @foundersfund, first pm & early eng @scale_ai; if you like infra, ML, or poker let's chat
Hifzullah @hifce
9 Followers 384 Following Building research tools at @ultradianai. Writing on evaluation methodology and multi-agent workflows. Discovered, not designed.
Ardalan Javadi @ArdalanJavadi4
372 Followers 2K Following Building BLUZAR | Founder of @thesecondpod | Ex- KavAi
Andrew Sohrabi @AndrewSohrabi
521 Followers 6K Following very forward deployed, exploring agents & inference / ex @palantirtech & @stripe / alum @ucberkeley / frmr @calhacks *all opinions are my own*
Sepehr 🇩🇪🇮�... @SepAhead
113 Followers 2K Following https://t.co/C0aTqVpUfi Harnessing AI to transform the physical world.
Vishesh Mittal @Vishesh_Mittal_
106 Followers 524 Following Multimodal Models @Amazon | prev. MLE @Qualcomm
Dany @dguevar1
252 Followers 5K Following
yuna @yunnaaac
2 Followers 80 Following
周万鑫 @Tmjor_zwx
0 Followers 38 Following
Ray Reynolds @RayReyn33182674
2K Followers 3K Following Yea I watch Folk who make sport but My purpose is to find unrepentant sinners and stay behind their rag until they ask YESHUA to redeem their Souls 📖✊💯
Sanyam Bhutani @bhutanisanyam1
42K Followers 1K Following 👨💻 Working on llama models @AIatMeta | Previously: @h2oai, @weights_biases 🎙 Podcast @ctdsshow 👨🎓 Fellow @fastdotai 🎲 Grandmaster @Kaggle
Bruce @CiroBinBin
0 Followers 48 Following
Claudia U. Faithwonde... @CFaithwonders
179 Followers 1K Following Founder social enterprise @fwonderstravels Independent Luxury Travel Advisor @hellofora Bringing your exclusive @virtuoso perks #community #faithwonders ✝️🌎🛳
Sandra @Sandra6z7j
21 Followers 1K Following
민식 채 @MinsigC21015
4 Followers 10 Following
Alan @Agaba53435351
518 Followers 4K Following Democratic capitalism. Ultra-libertarian. The Tea Party Movement. Socialism sucks.
Emre Guven @FerhatEmreGuven
5 Followers 137 Following
Jinyan Su @SuJinyan6
1K Followers 276 Following @Microsoft ; PhDing @Cornell; Prev: @AIatMeta @Stanford @AdobeResearch.
Aswin DG @dg_aswin
13 Followers 2K Following
AIcontributors @aicontributors
12 Followers 2K Following
Matt McAteer @MatthewMcAteer0
3K Followers 4K Following AI Agents @AIatMeta. Prev. @RealityLabs, early @OpenRouter, @imbue_ai, @Google. fmr. Longevity @DeepOriginBio @MGH. BitTensor co-author. @HF0. Pet-sitter
AK @_akhaliq
512K Followers 3K Following AI research paper tweets, ML @Gradio (acq. by @HuggingFace 🤗) dm for promo ,submit papers here: https://t.co/UzmYN5XOCi
Behnam Neyshabur @bneyshabur
44K Followers 1K Following Co-Founder & CEO @mirendil 💼 Past: co-led Discovery team @AnthropicAI & Blueshift team @GoogleDeepMind 🎒Traveling & Backpacking
Yann LeCun @ylecun
1.2M Followers 787 Following Professor at NYU & Executive Chairman at AMI Labs. Ex-Chief AI Scientist at Meta. Researcher in AI, Machine Learning, Robotics, etc. ACM Turing Award Laureate.
Ben Recht @beenwrekt
35K Followers 325 Following optimization. machine learning. uc berkeley. I blog at https://t.co/fkJujOPsJb The world won't end.
Lucas Beyer (bl16) @giffmana
144K Followers 619 Following Researcher (now: Meta. ex: OpenAI, DeepMind, Brain, RWTH Aachen), Gamer, Hacker, Belgian. Anon feedback: https://t.co/xe2XUqkKit ✗DMs → email
(((ل()(ل() 'yoav)))... @yoavgo
85K Followers 2K Following
Peyman Milanfar @docmilanfar
114K Followers 588 Following Distinguished Scientist at Google. National Academy of Engineering. Computational Imaging ∩ AI. Posts are personal opinions
Percy Liang @percyliang
110K Followers 425 Following professor of computer science @Stanford @stanfordnlp, co-founder of @togethercompute, creator of https://t.co/7R5THVogW2, co-founder of @simile_ai, pianist
Jim Fan @DrJimFan
501K Followers 3K Following NVIDIA Director of Robotics & Distinguished Scientist. Co-Lead of GEAR lab. Solving Physical AGI, one motor at a time. Stanford Ph.D. OpenAI's 1st intern.
rohan anil @_arohan_
44K Followers 2K Following member of technical staff & co-founder of @coreautoai - and continuing to aspire to understand deep learning.
Zhimei Ren @RenZhimei
1K Followers 320 Following Assistant professor @Wharton stats. Former postdoc @UChicago & PhD from @Stanford.
Natasha Jaques @natashajaques
34K Followers 1K Following Assistant Professor leading the Social RL Lab https://t.co/ykwfJG84Bj @uwcse and Staff Research Scientist at @GoogleAI.
Sam Bowman @sleepinyourhat
67K Followers 3K Following AI alignment + LLMs at Anthropic. On leave from NYU. Views not employers'. No relation to @s8mb. Into @givingwhatwecan.
Soumith Chintala @soumithchintala
313K Followers 1K Following Building new things @thinkymachines. Also dabble in robotics at NYU. Cofounded @PyTorch. AI is delicious when it is accessible and open-source.
Jason Wei @_jasonwei
110K Followers 719 Following ai researcher @meta superintelligence labs, past: openai, google 🧠
Sebastien Bubeck @SebastienBubeck
78K Followers 1K Following I work on AI at OpenAI. Former VP AI and Distinguished Scientist at Microsoft.
Techmeme @Techmeme
424K Followers 990 Following Top news and commentary for technology's leaders, from all around the web. This account shares top-level Techmeme headlines. Visit our site for full context.
Redwood City Police @RedwoodCityPD
18K Followers 414 Following The official Twitter feed for the Redwood City Police Department. We are actively hiring! Please check out our recruiting website. https://t.co/LDBnMZd64V
Roman Novak @ARomanNovak
480 Followers 284 Following Research Scientist @OpenAI, ex @GoogleDeepMind, Google Brain 🇺🇦
John Murzaku @jmurzaku
455 Followers 389 Following Coding Agents @SnorkelAI. Prev: Evals @adobe, PhD @stonybrooku
Tara Rezaei @tararezaeikh
6K Followers 455 Following co-founder @mirendil, mit ‘26, prev openai, prod
Mirendil @mirendil
7K Followers 0 Following Democratizing frontier AI R&D to accelerate science and technology.
"Leigh Marie" Braswel... @LM_Braswell
21K Followers 5K Following partner @kleinerperkins; previously investing @foundersfund, first pm & early eng @scale_ai; if you like infra, ML, or poker let's chat
Sanyam Bhutani @bhutanisanyam1
42K Followers 1K Following 👨💻 Working on llama models @AIatMeta | Previously: @h2oai, @weights_biases 🎙 Podcast @ctdsshow 👨🎓 Fellow @fastdotai 🎲 Grandmaster @Kaggle
Tom Brown @NotTomBrown
36K Followers 441 Following Co-founder and Chief Compute Officer @AnthropicAI
Lighthouse @lighthousehq_
8K Followers 14 Following The fastest immigration solution for the startup and technology industry 🇺🇸 We help the best get a US work visa seamlessly, so you can get back to building
English grammar @knowiiiedge
341K Followers 0 Following Learn English skills || Insightful Analysis || Communication || Vocabulary Building | | Grammar || Questions & Explanations!
Psyche Wizard @PsycheWizard
584K Followers 199 Following Giving you actionable advice to become the best version of yourself. Tweets and threads on self improvement.
The Assembly @InTheAssembly
510K Followers 4 Following Macro analysis, market structure, and the trades nobody else is showing you. Access closed. Not financial advice.
Kelly Buchanan @ICML @ekellbuch
2K Followers 2K Following @Stanford with @HazyResearch and @Scott_linderman. Working on 🤖🧠 PhD @cu_neurotheory @GoogleAI
Rohan Varma @rvarm1
1K Followers 656 Following @reflection_ai | prev: Jump Trading, Meta Superintelligence, @PyTorch
Becky Sosnov @BeckySalman
1K Followers 4K Following Building frontier open intelligence @reflection. Advisor, investor, storyteller. Former Head of Comms at @notion @doordash. Words matter.
Stephanie Zhan @stephzhan
32K Followers 2K Following GP @Sequoia, investing in AI, from company formation. 1st partner to @linear @mach_industries @middeskhq @reflection_ai @ricursiveai @skildai @tavus
Adam Abdulhamid @the_adam_a
66 Followers 361 Following MTS @ Reflection, prev. Wayve, Cruise, Stanford CS BS/MS
Brandon Amos @brandondamos
22K Followers 2K Following 🧙 RL @Reflection_AI past: @MetaAi @GoogleDeepmind @SCSatCMU @Cornell_Tech
Himanshu Sahni @sahnihim
471 Followers 200 Following Leading Science of RL @ Reflection. Previously: Deepmind, Tesla, Facebook, OffWorld, Microsoft. All views are mine.
litquidity @litcapital
1.3M Followers 1K Following founder @litquidityvc // newsletters @exec_sum & @cryptosum_ // @baincapvc scout // trade on polymarket: https://t.co/kXGzvIdxOS
Woosuk Kwon @woosuk_k
8K Followers 790 Following @inferact | @vllm_project | prev: PhD @Berkeley_EECS
Brian Zhan @brianzhan1
5K Followers 1K Following Partner @strikervp. Seed @ElorianAI, @SkildAI, @PeriodicLabs, @Reflection_AI, @DynaRobotics, @RicursiveAI, @humansand (angel), @LeptonAI (acq), @VoyageAI (acq)
Allan Cassis 🌒 @AllanCassis
2K Followers 4K Following Founder & CEO of @LvnaCapital (lu·na | /ˈlü:nə/) @HarvardHBS MBA @Columbia B.S. in Applied Math
Nikhil Ghosh @nikhilghosh101
315 Followers 609 Following Research Fellow at Flatiron Institute. prev: PhD at UC Berkeley Statistics
Epoch AI @EpochAIResearch
48K Followers 0 Following Investigating the trajectory of AI for the benefit of society.
*Walter Bloomberg @DeItaone
1.7M Followers 38 Following
Rohin Manvi @rohin_manvi
981 Followers 384 Following phd @berkeley_ai w/ @svlevine, prev undergrad @stanford @stanfordailab
CRV @CRV
39K Followers 300 Following CRV specializes in early-stage seed and Series A startups. We've invested in over 750 companies including DoorDash, Mercury and Vercel.
Hamid Palangi @hamidpalangi
2K Followers 930 Following Staff Research Scientist @Google, Affiliate Associate Professor @UW, Former Principal Researcher @MSFTResearch
Max Gazor @maxgazor
4K Followers 314 Following Partner @strikervp. Inception-stage VC, legendary founders. 5x Midas List. @reflection_ai @cribl_io @airtable @dynarobotics @ricursiveai @inferact @elorianai










































