Jon Xu @xuster
General Partner @YCombinator, Co-Founder @FutureAdvisor (YC S10), MIT EECS San Francisco, CA Joined June 2007-
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Your startup's growth rate is also its learning rate. Setting an ambitious growth goal and trying to hit it is the fastest way to find out what's broken and how to fix it. Not just the obvious stuff. Wrong customer, wrong problem, product nobody wants. It also stresses the founding team. You find out fast whether you can handle hard problems under pressure. Bottlenecks only show up when you push. If you're not having uncomfortable discoveries early, you're not pushing hard enough.
@charliermarsh Sometimes they're a good reason to work on something. When people say a market is "crowded," what that often means is that there's a real problem and none of the solutions are good enough yet.
Founders often ask me what to listen for in customer calls to know if they have a hair-on-fire problem. This is the wrong question. Can you run their business? If you were CEO, would this be a top 2 priority? Because most businesses never get to #3. Rather than pitching your idea, learn the business so well you could run it yourself. You'll know exactly how big the problem is and what they'd pay. And if this is going to 100x their business and they still won't buy? You just discovered the AI version of their company.
A mic drop moment @ycombinator tonight @sama just offered $2M in OpenAI tokens to EVERY YC startup in the current batch in exchange for equity Just like Yuri Milner offering to invest in every startup back when Sam was a YC partner I can't wait to see what's unlocked when you let the most driven, creative and formidable founders tokenmaxx
The YC application deadline is today. If you're working with AI to close the scientific discovery loop, drop an application and tell us about it.
We’re bringing Jensen Huang to Startup School for a fireside chat with @garrytan! From co-founding @nvidia in 1993 to building the backbone of the AI era, Jensen helped turn GPUs into the engine of modern computing. Apply to attend: events.ycombinator.com/startup-school…
This summer we're launching YC Paper Club to bring researchers & builders together. Every few weeks we'll host a small group dinner in Mountain View to share and discuss new research papers. Interested in both research & building the future? Sign up at: events.ycombinator.com/ycpaperclub
MIT student asked a question earlier today that a lot of young founders are quietly wondering about: "Won’t the frontier labs just do everything?" Yes it's true that OAI/Ant are shipping at incredible pace, but it's quite easy to avoid their blast radius and build amazing startups: OpenAI is not going to build a cattle-herding drone, buy an old F-150 and drive from ranch to ranch like the founder of one of the fastest-growing YC W26 startups, Graze Mate. Anthropic is not going to integrate with dental insurance verification systems (Lance). Google is not going to navigate NATO procurement (Milliray). The value is in the last mile, not the model. Sales cycles require humans who understand the customer. And most importantly, the market is expanding, not shrinking: AI isn't cannibalizing the existing 1% software spend — it's unlocking the other 5-6% that was going to humans. That's a much bigger market for startups yet-to-be-founded than the one the labs are playing in. Now, what DOES seem risky? A thin UI layer on top of ChatGPT with no domain expertise; a general-purpose chatbot or assistant; or a product that gets obsolete when model capabilities improve. But — tools for specific industries; "full-stack" AI companies that actually are the service (AI law firm, AI accounting firm, AI uranium exploration company); or generally products where the customer doesn't want a tool but an outcome — are defensible ideas for startups.
Grateful to have @demishassabis and @GoogleDeepMind stop by YC today and hang with founders!
Congrats to @astorinvest on their $5M seed! They're building an AI investment advisor for everyday investors. It connects to your brokerage, analyzes your portfolio, and delivers personalized recommendations. Less than two months after launch, thousands of users have already connected over $200M in assets to the platform. fortune.com/2026/04/23/jjj…
AI isn't just making teams more productive. It's changing how companies should be built. In this episode of Startup School, YC Partner @sdianahu explains what it means to build an AI-native company, where AI isn't just a tool but the operating system your company runs on. She breaks down how to make your company queryable so agents can improve across every function, why management hierarchies break down when an intelligence layer replaces human middleware, and why early-stage founders have a massive edge in building this way from day one. 00:58 - AI as your company’s operating system 01:57 - Open vs closed loop companies 03:00 - Making your company fully queryable 05:00 - The rise of the 1,000x engineer 07:12 - Why middle management disappears 09:12 - Startups will win this shift
Everyone thinks about money differently. The last generation of personal investment software was fine but not truly optimal for anyone. I know because I built one. AI unlocks a truly personalized advisor with deep understanding of financial situations and personal opinions. Excited that @brunokoba_ and @tulha_ are building this at @astorinvest. Congrats guys!
We (@astorinvest) raised a $5M seed led by Monashees, with participation from Goodwater, Gilgamesh Ventures, and other incredible investors. In less than two months after launch, thousands of users have connected over $200M in assets to our platform. We're just getting started.
The team at @10x_Science is delivering a huge unlock for drug development by increasing the speed of protein characterization by orders of magnitude. David, Andrew and Vishnu are an insanely talented team working on a huge problem! And they’re hiring.
Congrats to @10x_Science on their $4.8M seed! They're building AI for molecular-level protein characterization, a process that today requires specialized scientists spending weeks or months manually interpreting complex data. Their platform delivers the same insights in minutes.
That’s a wrap on YC Startup School India. Bengaluru, you really brought it. We can’t wait to see what you’re going to build.
@_groww is now a public company and is the largest investment platform in India. @lkeshre the founder and CEO is still the power user of the product he’s built and still talks to users today. Had the privilege of sharing the stage at Startup School India where he spoke about building a generational consumer company. We talked about product taste as being not just what looks good, but intentional design choices informed by an obsession with the customer. Lalit and how the team at Groww builds products exemplify this. Photo credit: @gcs319
YC startup school india avengers moment
@harshilmathur built the largest payment platform in India by being obsessed with his users, having relentless conviction in a competitive space and never losing the ability to move quickly, even today at their scale. Thank you for sharing the @Razorpay story with Startup School India.
Garry Tan @garrytan
875K Followers 6K Following President & CEO @ycombinator —Founder @garryslist—Creator of GStack & GBrain—designer/engineer who helps founders—SF Dem accelerating the boom loop
Dan Siroker @dsiroker
38K Followers 5K Following Founded and sold @Optimizely and @LimitlessAI. Created products considered impossible and made them inevitable.
Antonio García Mart�... @antoniogm
224K Followers 16K Following Director, @base growth. Founder @spindl_xyz (acq. @coinbase). Wrote bestseller 'Chaos Monkeys'. גם זה יעבור 🇺🇸🇪🇸
Jerry Lin @jerrylin
768 Followers 803 Following Formerly engineering at @square. Still no dietary restrictions.
Sachin Agarwal @agarwal
33K Followers 3K Following I ❤️ San Francisco. Co-founder @GrowSF. We’re helping get SF back on track by electing leaders who focus on outcomes. We’re the #1 voter guide in SF.
Y Combinator @ycombinator
1.6M Followers 364 Following We help founders make something people want. Subscribe to our newsletter: https://t.co/sjqjxxBeLc
Umesh @umeshs05
133 Followers 999 Following tweets on AI, Polity, Policy | चरैवेति चरैवेति… @carnegiemellon
Ayush @sangoleayush123
0 Followers 23 Following
Bhuwan @Bhuwanbibs
2 Followers 55 Following AI governance | Supply chain automation | Building practical AI products
The Standout Dev @chukwudinw43943
71 Followers 785 Following Software Engineer | Tech Enthusiast | Aspiring Entrepreneur | ☕ Lover of coffee & good conversations | Reader & Writer
Nathan @arcane_bloom
239 Followers 2K Following • Curiositymaxxing • ML + Software • UG @iitmadras '26 • Daily Learning Logs @senthil_twt
Vikash Chaudhary @VikashChau48094
3 Followers 108 Following
Animesh Sinha @AnimeshSinha13
78 Followers 163 Following Computer Scientist | Google | Ex-Optiver: Working on GenAI, retrieval, computer vision.
First Bight Ventures @FirstBight
2 Followers 81 Following The leading US-based early stage venture fund focused specifically on synbio and industrial biotech.
Harshit solanki @_harshitsolanki
156 Followers 487 Following I make launch videos | 19 | GTM https://t.co/3SC8SEfNNE | ex-CD @residencyBLR
Shiva Reddy @ShivaRe30346144
1 Followers 158 Following
Lakshay @Lakshxysharma
3 Followers 8 Following Building https://t.co/P6eFjfSZq0 https://t.co/HfpDmCmFJ7
Tuomo Nikulainen @tuomonikulainen
10 Followers 73 Following Building Pisama: failure detection for agentic AI systems. Catch loops, drift, and silent failures before your users do.
Winston Brown @WinstonBrown_
282 Followers 836 Following a superposition of destiny and entropy | 32,768hz | Building a 'bot vs bot' chess portal https://t.co/fYRjOjfmrb | https://t.co/nuPA0Pa7EN
Jake Swent @jakeswent
0 Followers 11 Following
Mukhtar Ahmed Ajibola @KoredeAhmed1
58 Followers 1K Following Founder of VerseCity | Entrepreneur | B.Eng. in Mining & Mineral Engineering | Software Engineer | Writer & Poet
Kamil Shah @kamilshah195
0 Followers 295 Following 🇵🇰 Data Science Student Exploring AI, ML & startups Nothing Engineer @OpenAI
דניאל אטיאס @dnyltys256899
16 Followers 245 Following
Ryan Loh @ryanlohyr
179 Followers 253 Following Building LearnKata | Prev @HockeyStackHQ (YC S23) @GovTechSG |📍🇸🇬/🇺🇸
Lucas Mitre, MD @Lucas_Mitre_
2K Followers 2K Following 🩺MD Postdoc @MAIA_laboratory @UTSWMedCenter | @FCMSCSP 24’ | ECFMG certified 🧠Interested in Neurosurgery, Radiosurgery and AI 🦾
Vivek ⏻ @vivekdotcurious
91 Followers 4K Following Currently rebuilding my Curiosity. Ex-Engineer @salesforce @ncr_voyix Masters dropout @iiit_hyderabad
Abishek Arjun @AbishekArjun4
0 Followers 87 Following
Basel Rashwan @BasilMohmaed
3 Followers 64 Following
Rohit Patil @Rohitpatil5
713 Followers 7K Following Engineering @maximor_ai. Previously built customer experience tech for millions at @PhonePe_ and valuation engine at @IONCommodities. Views are of my own.
Manavi Garg @GargManavi
218 Followers 856 Following figuring out what I can build | ex - Meesho, HUL, IIT Delhi
Himanshu Singh @nocap_himanshu
2 Followers 72 Following Building the future of learning | Product & Generalist
disha @lla_dawn
92 Followers 796 Following finding my next obsession with a team | solo building @mumblwtf the working-memory layer for teams | prev eng @useTria @eth_barcelona @DoinGudHQ
Kshitij Kumar @KshitijCodes
11 Followers 611 Following Software Engineer | AI Agents, LLMs, Python, TS, Java, Microservices | MSCS@SUNY Buffalo | Founder-Like Mindset
GNANENDAR KUMAR @GnanendarK48050
0 Followers 50 Following Developer & Entrepreneur | Building from the ground up | Turning ideas into products | Tech | Startups | Growth
Puneet (99%+ accurate... @puneetjindalisb
317 Followers 2K Following discuss data curation, synthetic data, data annotation and collection, computer vision, generative AI, Robotics https://t.co/9hYFNQ51pC
Ali Khademhosseini @khademh
21K Followers 2K Following Scientist and entrepreneur; 3X Founder; Ph.D. @MIT; x-Prof @Harvard & @UCLA; x-CEO at TIBI; x-Scientist @Amazon.
Ansh @ansh_chokshi
169 Followers 631 Following building @ mireye, prev founder ceo of poker pit (acq), cs @uoft
Peter Beguely @PBeguely
0 Followers 63 Following
Ansel Dias @AnselDias
1K Followers 1K Following Founder, CEO @ AutoFAB | Building Robots that Build Robots Faster and Cheaper | @theresidency | DMs open
ankush @ankushKun_
2K Followers 2K Following Building an AI OS for businesses @use_construct; I build tools to improve DevX; prev. @fwdresearch @arweaveindia;
Kirill V @secretkirusha
10 Followers 218 Following UC Berkeley EECS+MechE // Scientific Humanism // Strictly Personal Opinion
Chiranjeev kapoor @chiranjeevkap
193 Followers 4K Following Physics is the law, everything else is just a recommendation. Working on RAG and Agentic AI. Research & Development @ Nokia
Sarabjot @rubbervduck
50 Followers 3K Following Computer Vision @ Posha | Exploring computer vision, pixel by pixel.
Nanyondo Allen @Nanyondo_Allen
1 Followers 49 Following Passionate about AI, cognitive science, coding & sustainable innovation | Youth leader building solutions for tomorrow
Shai Novik @snovik
614 Followers 63 Following Executive Chairman @Enlivex. Ex-PROLOR ($590M exit). Architecting a dual-strategy company: Quality Longevity development powered by prediction market treasury.
Paul Graham @paulg
3.2M Followers 791 Following
Garry Tan @garrytan
875K Followers 6K Following President & CEO @ycombinator —Founder @garryslist—Creator of GStack & GBrain—designer/engineer who helps founders—SF Dem accelerating the boom loop
Yuri Sagalov @yuris
28K Followers 653 Following Dad, husband, brother, son, friend, founder, investor (@Supabase, @WeAreLegora, @DecagonAI,+++). MD @GeneralCatalyst. Previously @WayfinderVC @YCombinator.
Alexandr Wang @alexandr_wang
491K Followers 858 Following chief ai officer @meta, founder @scale_ai. rational in the fullness of time
Antonio García Mart�... @antoniogm
224K Followers 16K Following Director, @base growth. Founder @spindl_xyz (acq. @coinbase). Wrote bestseller 'Chaos Monkeys'. גם זה יעבור 🇺🇸🇪🇸
Jerry Lin @jerrylin
768 Followers 803 Following Formerly engineering at @square. Still no dietary restrictions.
Harry Stebbings @HarryStebbings
463K Followers 374 Following 🎤 @twentyminutevc, 🏦 @20vcfund, @projecteurope_😇 @fuseenergy @linear @wearelegora @factoryai @lovable @airwallex @mercor_ai @workos
Patrick OShaughnessy @patrick_oshag
340K Followers 2K Following building @psumvc @colossusmag hosting @investlikebest
Benjamin Ling @bling0
21K Followers 1K Following Founder and GP at @blingcapital, GP @khoslaventures, Fitness junkie, formerly @YouTube @Google @Facebook
delian @zebulgar
272K Followers 938 Following space drugs and arms @vardaspace | village idiot/partner @foundersfund | porthos @hillvalleyforum
Sachin Agarwal @agarwal
33K Followers 3K Following I ❤️ San Francisco. Co-founder @GrowSF. We’re helping get SF back on track by electing leaders who focus on outcomes. We’re the #1 voter guide in SF.
Y Combinator @ycombinator
1.6M Followers 364 Following We help founders make something people want. Subscribe to our newsletter: https://t.co/sjqjxxBeLc
Yahia Bakour @mynameisyahia
5K Followers 2K Following @getcontextdev (YC S26) - One API to scrape, enrich, and understand the web
conor brennan-burke @contextconor
9K Followers 3K Following founder @hyperspell (yc f25) your company brain
Andrew Miklas @amiklas
2K Followers 77 Following
Finbarr Taylor @finbarr
6K Followers 864 Following Visiting Partner @ycombinator. Founder & former CTO & CEO @Shogun. Angel investor in 60+ companies. Startups, the universe and everything. 🏴
Abhishek Sharma @oneabhishek
4K Followers 822 Following Tech & AI @NexusVP • 💙 Distribution, PLG, OSS
Philip Johnston @PhilipJohnston
25K Followers 773 Following Co-founder & CEO of @Starcloud_ - Building data centers in space.
Mathilde Collin @collinmathilde
24K Followers 1K Following Co-founder & Exec Chair at @FrontHQ. Angel investing. KORA.
Tom Blomfield @t_blom
78K Followers 926 Following Partner at @ycombinator Cofounded @gocardless and @monzo
Sam siavoshian @samsiavoshian
477 Followers 1K Following GTM eng @ReacherApp YC (S25) | 6x hackathon winner | Founder of @ArenaAiApp | Yes, I'm still in high school
Manufact @manufact
949 Followers 53 Following Helping dev teams build and deploy MCP servers / ChatGPT Apps / Claude connectors mcp-use is building open-source dev tools and infra for MCP - @ycombinator S25
Vivian Midha Shen @vivianmshen
28K Followers 766 Following visiting partner @ycombinator. planning in centuries @amppublic.
Brontë Kolar @BronteKolar
469 Followers 375 Following cofounder @zeonsystems // making robots do science
Ryanair @Ryanair
925K Followers 58 Following Catch flights, not feelings with Europe’s no. 1 airline 💅
Jerry Wu @Jerr_Wu
359 Followers 879 Following RL environments for knowledge work Founder @ https://t.co/tzjRHkYIfF CS/ML @cornell.
Grey Baker @greybaker
2K Followers 257 Following Visiting Partner at @ycombinator. Previously co-founder of @pincitesai (acq. by @filevine) and @dependabot (acq. by @github). Employee #3 at @gocardless.
Aakash Gupta @aakashgupta
271K Followers 826 Following ✍️ https://t.co/8fvSCtBv5Q 💼 https://t.co/STzr4nqxnm 🤝 https://t.co/SqC3jTyP03 🎙️ https://t.co/fmB6Zf5UZv
GLADIA Research Lab @GladiaLab
5K Followers 25 Following Based in Rome, GLADIA is a team of computer scientists, physicists, engineers and mathematicians venturing beyond the boundaries of machine intelligence
Hubert Thieblot @hthieblot
58K Followers 3K Following Investing @fdotinc, Founder @curseforge acq by @Twitch, love @oheather1337, 3x dad, 🇫🇷🇨🇭🇺🇸
Christopher Golda @golda
4K Followers 965 Following VGP @YCombinator. Investor @Apex_Satellites, @Benchling, @Coinbase, @Ollama, @PierreComputer, @Resend, @Stoke_Space, @Supabase, @UseCorgi, more
Omar Khattab @lateinteraction
36K Followers 3K Following asst professor @MIT CSAIL @nlp_mit. https://t.co/VgyLxl0VZz, https://t.co/ZZaSzaRIOF (@DSPyOSS), RLMs, GEPA
Arnav Sahu @arnavsahu341
6K Followers 866 Following Partner @peakxvpartners (fka Sequoia India) in Bay Area. Ex-@ycombinator, @sparkcapital, @appdynamics, @blackstone @wolfia_app. Underdog. I love 🫡 emoji.
Arlan @arlanr
22K Followers 3K Following 19, ceo @nozomioai (yc s25) | kicked out from high school, stanford research at 16
Ashley @ashlleymo
258 Followers 138 Following co-founder @liva_ai (yc s25) | prev cs @caltech | sometimes i dance
Raphael Schaad @raphaelschaad
27K Followers 1K Following Visiting Partner @ycombinator, helping founders build iconic startups. Swiss designer, MIT engineer, founder Cron (acq by Notion). I run through forests.
Harshita Arora @aroraharshita33
15K Followers 464 Following General Partner @ycombinator. Co-founder of AtoB (https://t.co/K4GSvO9VhC).
Supabase @supabase
200K Followers 99 Following The Postgres development platform. 🌐 https://t.co/kHsst88XA1 ⭐️ https://t.co/txGagqok1i 🎥 https://t.co/6eTjCTIrzK 💬 https://t.co/ikFm89oPVI
Lewis 🇺🇸 @ctjlewis
46K Followers 21K Following Startup counterculture. LLMs. If you think I might be able to help you with something, ask.
Shengjia Zhao @shengjia_zhao
52K Followers 235 Following Chief Scientist @ Meta MSL. Formerly MTS @ OpenAI, PhD @ Stanford. I train models. All opinions my own.
Prem Qu Nair @premqnair
6K Followers 1K Following @cognition/@windsurf, previously @nuro @princeton. Pursuing 70mm, 225lb, and $0.10/piece
Alda Leu Dennis @AldaLeuDennis
2K Followers 269 Following investing @Hawktail Board Partner @Initialized
René Brandel @renebrandel
2K Followers 1K Following building @getcasco (YC X25) | invented @kirodotdev, ex-@awscloud, ex-@microsoft, ex-@skype
Charlene Wang @hsinleiwang
1K Followers 668 Following CEO & Co-Founder, @EmberCopilotAI. Formerly, @Google Health.
Kim-Mai Cutler @kimmaicutler
58K Followers 32K Following Partner at @initialized. When life hands me lemons, I make tarte au citron.
Arfur Rock @ArfurRock
40K Followers 5K Following anon GP at your favorite multi-stage VC // OS intel for the private markets
Mustafa Suleyman @mustafasuleyman
551K Followers 495 Following CEO, @MicrosoftAI | Author: The Coming Wave | Past: Co-founder, @InflectionAI & @GoogleDeepMind





























