Co-founder & CEO of Discovery Loop. Former Chief Scientist, Google. Helped build many Google products, TPUs, Gemini, TensorFlow, MapReduce, Bigtable, ...

Joined September 2017
In April, '17, @jsomers of @NewYorker reached out & said he wanted to do a small profile of me & my longtime colleague Sanjay Ghemawat, watch us work for a few hours, maybe dinner, etc. It came out today. I think it captures our working style really well. newyorker.com/magazine/2018/…
409
1,204
249
5,909
Jeff Dean retweeted
I’m starting a new early-stage AI fund, doing what I love: partnering with founders from company formation on bold bets, long before consensus. The fund’s LPs will include Sequoia, Jeff Dean, Sachin Katti, Philip Wong (my Stanford professor and Chief Scientist adviser to TSMC), and others whose work has shaped our industry and how I think about AI’s future. I’ll remain a partner at Sequoia and keep serving on my boards on Sequoia’s behalf. Sequoia has been my home for the past 11 years. I joined as the youngest investor the firm had ever hired. I grew up here. Through years of intense debate and shared work, I found lifelong mentors and friends who took me under their wing and taught me this craft. They taught me to aim high and take big swings. I’ll carry that into what I build: outsized ambition, relentless truth-seeking and curiosity, and a refusal to become complacent. Working alongside founders has made me want to build something of my own: a firm shaped from day one around the convictions I’ve developed over the past decade. Life has taught me not to take time for granted. This is how I want to spend mine. Why now We’re seeing a new way of building companies in today’s AI era. Research and products often advance together. A breakthrough can open a market or accelerate a business far faster than expected. Some companies require extraordinary capital and compute early on. Others reach meaningful scale with remarkably small teams. The rules for how big these businesses can get, and how fast, are being rewritten. But early on, the technology is unproven, the resources required enormous, and the vision seemingly implausible. This is what I love most: seeing the potential right from the beginning, and helping founders realize their full scale of ambition. More than ever, it starts with an extreme willingness to believe early, with bold, independent conviction in a founder’s technical insight before any product or market validation. Then, it means helping founders take the biggest swings, giving the rare, long-term patience to see those bets through uncertainty, ambiguity, and turbulence, and serving as a level head when the stakes are highest. I learned this kind of partnership at Sequoia. It’s the foundation of the firm I’m building. Believing before consensus My fascination with AI’s potential took root at Stanford in the early-to-mid 2010s, studying computer science and working in Andrew Ng’s lab. The friendships I formed connected me to a community whose people and ideas would help shape modern AI and build some of our generation’s defining companies. What stayed with me was the gap between what those people saw was possible and what the wider world could imagine. I’m drawn to founders pursuing ambitions that sound impossible today. I start with a simple question: “What if everything goes right?” Then we work backward together to make it happen. In 2023, Deepak and Abhinav set out to build a general-purpose robot brain at @SkildAI, before physical AI was a consensus bet. Their sim-to-real breakthroughs gave me conviction where earlier robotics approaches had fallen short. But the data flywheel required deployment at scale. We made commercialization as urgent as research and brought in strategic partners like NVIDIA and SoftBank to support the ambition. Three years in, Skild is advancing the frontier of physical AI with nine figures in annualized revenue. In 2024, Ioannis and Misha founded @reflection_ai with an insight into scaling reinforcement learning. As that grew into the ambition to build a Western frontier lab for open models, the hard question was how a startup competes with labs spending tens of billions. An introduction to NVIDIA and many compute calls and recruiting events later, the team has built Beam, now one of the leading US open models. In 2025, Anna and Azalia, the co-creators of AlphaChip, founded @RicursiveAI to design models and hardware together. From day one, we made early customers and ecosystem partners a priority. Today, they are showing order-of-magnitude improvements on real workloads, working with some of the industry’s most consequential players, and reaching a defining inflection point. The ambition keeps growing as these companies scale. @linear has always had a kind of magic to it. Now it’s the system a new generation of AI companies builds on, for teams and agents alike. @tavus saw early that we’d one day talk to AI the way we talk to each other. Today, it’s building the human computing interface for a world of AI colleagues. @Mach_Industries began as hydrogen experiments in an MIT dorm room. It has since become one of the most exciting next-generation defense companies. Making the ambition possible Being a first believer is only the beginning. Compute falls through. A deep-pocketed incumbent makes your mission its top priority. A breakthrough changes the opportunity and the capital required overnight. These are stomach-churning moments, and early belief carries a responsibility to help make the bet work. This is the partnership I love: turning the full ambition into concrete steps. Raising capital, securing compute and strategic partners, recruiting exceptional people, and winning the first customers together. Thinking several moves ahead while solving what’s in front of us. And as breakthroughs open new possibilities, helping founders dream even bigger. Thank you To the founders I’ve worked with: thank you for trusting me and Sequoia to be your first partner and first believer. It’s been the joy of a lifetime, and I can’t wait to keep building together. Thank you to Alfred and Pat for your leadership of Sequoia and your support of my next chapter. To Roelof, for bringing me into Sequoia and believing in me from the beginning. Alfred and Roelof, you have been mentors in investing and in life. So much of what I know, and the investor I’ve become, comes from your guidance and generosity over the years. To Bill, for the close partnership and wealth of knowledge, always wrapped in humility. To Shaun, for showing me how to think deeply and imaginatively. To Michael Moritz, for inspiring 22-year-old me to dream big. To Doug, for teaching me to keep things simple. To Bogie and Jess, for bringing joy to the everyday and perspective on what matters. And to all my Sequoia teammates, for the friendship, camaraderie, and lessons I’ll carry with me. To my family, especially my husband and my brother, who have each started companies of their own: thank you for giving me the courage to take this leap. Let’s get to work!
205
41
43
1,007
82,903
Jeff Dean retweeted
I launched the first image and video generation models at Google, and kept asking why all AI designs look the same. AI has brought us the WORST era of design. It made content creation effortless, but it also made 90% of it look painfully generic. My co-founder and I spent 2 years building in stealth to change that. Meet Vyb, the first AI design model that understands your taste like a designer would. RT + comment your website URL and we’ll make your first design.
270
237
195
2,038
3,641,120
Cancer patients with the same diagnosis often have very different tumor biology. Molecular testing can reveal underlying differences, but that's slow and expensive. Introducing Holon-S1, our platform to predict genes and biomarkers from routine pathology slides. • beats two other models at predicting spatial gene activity in a controlled comparison • has identified potentially novel biomarkers in breast cancer and colon cancer • evaluated across 16 organ types and more than 15 scanners, using slides from both formalin-fixed, paraffin-embedded and fresh-frozen tissue. We believe Holon-S1 has the potential to help researchers find new biomarkers in slides they already have, discover treatment targets, and bring more personalized cancer care within reach!
166
338
75
2,552
219,118
Have a glimpse at this! Nice work, @AndrewDai and Elorian folks!
Spent years watching models ace a single image and completely whiff on anything that moves or changes angle. Today we’re fixing that. Try Glimpse now, our first visual thinking model with competitive frontier performance compared to Astra on key public visual reasoning benchmarks.
40
50
5
819
102,406
My AI security research lab AISLE discovered 500+ zero-days with CVEs across 100+ codebases in a year => ~1% of 2026's open-source CVEs globally from a single team! On hardened codebases like curl, we've repeatedly matched or outperformed frontier AI labs in zero-day discovery
9
17
3
159
30,152
I've been a personal supporter (through our family foundation) of @Khipu_AI & @DeepIndaba, which are fantastic events for AI researchers in Africa and South America. I've encouraged Google to support these in the past. Discovery Loop (@DiscoLoopAI) is thrilled to support!
For the last 10 years we've been raising funds to bring AI to Africa (@DeepIndaba) and South America (@Khipu_AI). The efforts have been very successful, but this year we are finding it hard to raise money. If you work for an AI company, please share the following with the right team to support us. Thank you! About KHIPU 2027 What it is: KHIPU AI (khipu.ai) is a non-profit organization dedicated to advancing AI talent, research, and community across Latin America. Alongside year-round regional initiatives, we host a biennial in-person gathering rotating across the continent, previously in Uruguay (2019, 2023) and Chile (2025). Next Edition: April 5–9, 2027, in São Paulo, Brazil, hosted at the Universidade de São Paulo (USP), one of Latin America's leading research universities. Watch our 2-minute video: youtube.com/watch?v=Db19zoqu… (hear directly from past speakers, including Nando, and Latin American students on how KHIPU grew from a single gathering into a regional AI movement). Who Attends & Why Support - Engaging with the region's top talent and lab leaders: We bring together around 500 participants, including leading faculty and lab directors from across Latin America alongside a curated cohort of ~300 graduate students and industry researchers selected from over 1,000 applicants. As the local AI ecosystem grows rapidly, KHIPU offers a rare opportunity to engage directly with these emerging researchers and regional leaders in one place, helping shape research priorities and the safety mindset across Latin America while connecting with talent and perspectives outside Silicon Valley. 100% free attendance & student grants: Attendance is completely free for all selected students, professors, and researchers. Sponsorship funding goes directly toward travel and accommodation grants for students and faculty across Latin America who otherwise could not afford to attend. Community & Track Record: Past editions have featured speakers such as @Yoshua_Bengio , @JeffDean , @jpineau1 , and @NandoDF (2025 lineup: khipu.ai/khipu2025/speakers-…), and have been supported by the Hopper-Dean Foundation, @GoogleDeepMind , @Apple , @Microsoft , @Meta, @cohere , and @MistralAI . For 2027, @OriolVinyalsML and @sarahookr are already confirmed. 2027 Sponsorship Prospectus: Attached (also available at khipu.ai/prospectus-2027) Contact: @FortunatoMeire ([email protected]) & KHIPU Sponsorship Committee ([email protected])
40
45
3
711
67,222
As @NandoDF suggested, if you're at an AI company, please suggest to the appropriate person that these are worthwhile events for your company to sponsor.
4
2
1
37
12,089
Jeff Dean retweeted
Introducing DeepRSI, a new industry standard for measuring recursive self-improvement. On preexisting benchmarks, tasks are contributor-based and short-horizon (~12 hrs). In DeepRSI, we push agents to work 48 hours on ML tasks actually derived from ongoing proprietary research.
181
188
54
1,667
196,229
Wrapping up my first month at @DiscoLoopAI (am on leave from @PrincetonCS and @PrincetonPLI ). Excited to work on using AI to accelerate scientific discovery and solve important problems. My first startup experience, and with an incredible set of colleagues!
Announcing Discovery Loop! I am very excited to announce that, along with my longtime friends and collaborators @Sanjay_Ghemawat, @OriolVinyalsML and @quocleix, we are founding Discovery Loop (@DiscoLoopAI), a Public Benefit Corporation whose mission is to automate machine learning, science, and engineering to accelerate discoveries and progress. The four of us have worked together for 14 to 30 years, and have helped build some of the world’s most used products, infrastructure and AI models, and we’re excited to turn our attention to this ambitious endeavor. ♾ Learn more at: discoveryloop.com
30
41
2
854
61,926
We’re sharing new results showing that frontier AI models are able to outperform human experts on financial predictions for the first time. We built an environment for the challenging task of Earnings Predictions, finding that the most recent frontier models (Opus 5.5, Fable 5.1, Astra) with Samaya’s harness, meaningfully outperform expert consensus predictions on commonly reported earnings metrics such as company revenue, gross margin and more. We built this environment to have a “point-in-time” gate in the harness to ensure no information leakage, and created financial retrieval and data tools that would respect this gate and give the models access to the same information available to experts. We also adjusted for bias in expert consensus to create a hard, bias-corrected baseline, where outperformance has real signal. Only the most recent frontier AI models are able to beat this hard baseline, pointing to an important inflection point in AI capabilities in finance. Like with FrontierFinance, we see substantial headroom for further RL training in this environment — the models show large variations in error across different rollouts. We’re continuing research on using earnings prediction and other predictive tasks to post-train models to learn from their mistakes. Get in touch if you’d like to collaborate or try out an alpha version. Link to the full research below.
19
42
6
258
33,377
Jeff Dean retweeted
Proud to share that @phinity_ai is coming out of stealth today, announcing our seed fundraise and that we’ve reached 8-figures in annualized run rate. Chip design has been stuck in the 20th century for far too long. Now, for the first time in decades, a unique set of emerging factors is making it possible to fundamentally reinvent how chips are designed. At Phinity, we’re building toward fully autonomous chip design, with the goal of enabling custom silicon for thousands of emerging AI applications. Our team combines hardware experts, AI researchers, and infrastructure/EDA engineers to define a new way to design chips. We’re extremely grateful to @uncorkcap for leading our $5.2M seed, to @MoxxieVentures and angels including @JeffDean for joining the round, and to @pearvc for leading our pre-seed and backing us from the start. We’ve worked so, so hard to make this happen, and I’m proud to share our work publicly for the first time! You can read more about the announcement below. phinity.ai/blog/introducing-… We’re hiring for ops and engineering roles. If you want to help build the future of chip design with us or are interested in learning more/partnering, please reach out to me or @sonyashijin .
64
20
4
167
16,227
Jeff Dean retweeted
Excited to finally share that @phinity_ai is now out of stealth! We're announcing our seed fundraise and that we’ve reached 8-figures in annualized run rate. We’re already working with some of the largest foundation model labs. Our mission is to build fully autonomous chip design so AI can help us search beyond the limits of human engineering and discover computational systems we would never find on our own. We’re fortunate to have the support of @uncorkcap, which led our $5.2M seed round, with participation from @Moxxie including @JeffDean, following our pre-seed led by @pearvc! It’s been an amazing few months, and I couldn’t be more grateful for the opportunity to build the future of chip design with such a talented team. You can read more about what we’re building and why in our full announcement. phinity.ai/blog/introducing-… We’re hiring across all disciplines - if you’re interested in working with us, please reach out to me or @aadi_nash.
56
29
12
200
30,880
Very sorry to hear this news. 😥 I never had the chance to meet Margaret Hamilton, but her contributions to the flight software that got us to the moon are legendary. I love this image of her standing next to the printouts of the Apollo code.
We’ve lost an icon. Margaret Hamilton, a computer science pioneer best known for her work at MIT leading development of the flight software for the Apollo missions to the moon, has died at 90. Read about her legacy via MIT News: news.mit.edu/2026/margaret-h…
64
465
24
6,338
361,119
Proud to have collaborated with many others on quite a few of these things!
claude just generated this 2 minute video about the history of Google and it goes so goddamn hard
60
110
5
3,222
325,733
Jeff Dean retweeted
We are excited to announce a new faculty position in AI for Biology at UC Berkeley, jointly between @Berkeley_EECS and @CCBBerkeley. Please repost & share this opportunity with outstanding early-career researchers in your networks. Apply by Nov 9, 2026: aprecruit.berkeley.edu/JPF05…
2
64
4
274
36,510
The safety data for Waymo gets better and better. Comparison w/ human drivers on rate of crashes with serious injury: Latest data: 270M miles, 20X better Mar 2026: 170M miles, 13X better Before that (forget exactly when): 10X better
270M+ miles. 841 fewer injury-causing crashes. Our latest safety data shows the Waymo Driver continues to make roads safer for everyone. Compared to human drivers across 5 territories, it reduced: 📉 Injury crashes by 82% 📉 Serious injury crashes by 95% Full data: waymo.com/safety/impact
71
181
31
2,352
222,713
Jeff Dean retweeted
Every French🇫🇷 passenger train, on an ordinary Tuesday, from first departure to last
210
2,598
327
20,542
3,782,502
This was recorded a few months ago when I was still at Google and it was a really fun conversation!
How does this only have 21,000 views in 8 days? Chat with @JeffDean (then Google) and Bill Jia about large scale AI models. youtu.be/BVQSWeK2Nrw?si=MvMX…
18
42
1
746
107,931
Did you know you can learn interesting things from computations in real rat neurons? I love what @AlexKsendzovsky and team are doing at @BioComputingCo are doing.
What happens when neurons meet silicon? A new world emerges. Partnering with Amazon to bring it to customers. DM me for early access.
24
64
4
650
97,686
Luiz André Barroso’s work influenced me a lot in how I think about systems, and even about my career. I decided to write about his work with @JeffDean on some topics that interest me a lot: tail latency and the systems behind the modern internet. andreybleme.com/2026-09-22/l…
5
7
50
12,249