YesPress Profile
David
Winer
Co-Founder & CTO - Ciro (YC S22) - San Francisco
The mathematician who decided the worst part of sales was a software problem.
Founder
CTO
YC S22
AI / GTM
B2B SaaS
YesPress Profile
Co-Founder & CTO - Ciro (YC S22) - San Francisco
The mathematician who decided the worst part of sales was a software problem.
Profile
He calls himself an "exceedingly obscure internet personality" on Instagram. The people buying his software might disagree. David Winer is co-founder and CTO of Ciro - the AI-powered go-to-market platform that has quietly become the thing sales teams actually want: a system that figures out who to call, finds their contact info, and drafts the first message, all before a human touches a keyboard.
His path here is not the typical "dropped out at 19" arc. Winer collected credentials with unusual care - applied mathematics at Brown, electrical engineering and computer science at Berkeley, an MBA from Stanford - then spent time learning what each credential actually meant in practice. Bain taught him how to structure problems. Pure Storage taught him what "production at scale" feels like when something breaks at 3am. Google taught him something rarer: what it takes to design a tool that millions of developers will choose to use every single day.
At Google, Winer was product manager for Kotlin - the programming language that now powers the majority of Android apps worldwide. He sat on the Kotlin Foundation Board as its Secretary, shaping language decisions that affected every Android developer on earth. That is not a typical PM job. It requires understanding both the engineering constraints and the developer psychology simultaneously, and it turns out that combination is exactly what you need when building AI products that have to feel effortless.
Before Ciro, Winer co-founded Wage, a startup that raised $5M. The lessons from that experience - what worked, what did not, and how quickly "almost working" can become fatal - went directly into how Ciro was designed. The three co-founders - Winer, Richard Lee, and Ross Geiger - all met at Brown. Two decades of knowing each other's working styles is a different starting point than most founding teams get.
Ciro entered Y Combinator's Summer 2022 batch and raised a $3.8M seed round led by CRV, with Y Combinator and SV Angel participating. The bet was direct: sales prospecting is broken by tedium, not difficulty. A sales rep spends hours every week on work that produces a list of names. An AI can do that in minutes. Ciro built the AI.
The platform now scans more than 500 million profiles, detects buying signals, pulls verified contact data from 15 or more sources, and generates five to eight qualified meetings per week for its users - entirely automatically. In May 2025, Ciro launched publicly on Product Hunt and hit number two product of the day with 633 upvotes. The GTM community, it turns out, had been waiting.
Friction-free prospecting: from "Who should I target?" to "Meeting booked."- David Winer, Co-Founder of Ciro
Career
Achievements
Sat on the board governing one of the world's most widely-used programming languages - shaping decisions that affected every Android developer on the planet.
Led CRV, Y Combinator, and SV Angel to back Ciro's vision for AI-driven go-to-market automation.
Ciro's 2025 public launch earned 633 upvotes and #2 Product of the Day - organic validation from exactly the community that matters.
Wage ($5M raised) before Ciro. The failure modes from the first company went directly into the architecture of the second.
Education
The Company
Ciro's AI scans 500M+ profiles to identify ideal customers based on your ICP. It ranks every contact for fit and detects real-time buying signals before competitors do.
The AI researches each prospect and drafts personalized, contextual messages. No templates. No mass blasts. Outreach that reads like a human wrote it - because the research behind it is real.
The full loop closes in your Slack. From "who should I target?" to a meeting on the calendar - five to eight qualified meetings per week, per rep, with minimal manual effort.
Salesforce or HubSpot integration sets up in 15 minutes. Verified contact data pulled from 15+ sources. Prospect lists built in under five minutes.
Anthropic Claude and OpenAI power the intelligence layer. Elasticsearch handles the indexing. Node.js, React, and Tailwind handle the rest. Production-grade from day one.
Targeted at sales teams that can't afford to hire an army of SDRs. The AI becomes the research and sequencing layer they could never justify paying for before.
Technology
Fun Facts
The Bigger Picture
The timing argument for Ciro is simple and Winer makes it precisely: sales prospecting is fundamentally a data and research problem, not a human judgment problem. You're looking for people who match a profile, checking whether they have budget and pain, and finding a way to start a conversation. Large language models are excellent at all three parts. The human element - the actual relationship, the negotiation, the close - that stays human.
What makes Winer's background particularly relevant here is that he's spent his career at the exact intersection of data engineering and product design. Pure Storage gave him the infrastructure chops. Google Kotlin gave him the ability to think about developer experience at scale - how a tool needs to feel to get adopted and stay adopted. Bain gave him the vocabulary for business problems. Wage gave him the scar tissue from building something real and watching it evolve in ways you didn't predict.
Ciro's architecture reflects this. The platform uses Anthropic Claude and OpenAI at the intelligence layer, Elasticsearch for the indexing problem (500M profiles is not a casual technical challenge), and a clean React and Tailwind frontend that makes the complexity invisible to the end user. A sales rep does not need to understand the data infrastructure. They need to see five good prospects in their Slack by 9am.
The founding team structure matters too. Richard Lee runs as CEO, bringing COO experience from BuildZoom and consulting from Bain. Ross Geiger holds the President role with VP of Sales experience from YAPI and operating partner background from M33 Growth. Winer handles the technology. Three people with different scars, the same starting point (Brown's applied math department), and a shared theory about what's broken in B2B sales.
CRV's Anna Khan led the seed round, which is worth noting - CRV has a pattern of backing companies solving infrastructure-level problems in large markets. The framing of Ciro as "GTM AI" rather than "sales tool" is deliberate: the vision is not a feature on top of Salesforce but a new layer of the go-to-market stack.
Winer keeps a personal blog at davidjwiner.com where the work is more eclectic than you'd expect from a CTO: statistical analysis of TV show quality over time, voter targeting experiments using Twitter data, essays on moving to the Bay Area. It is the blog of someone who is genuinely interested in data as a lens for everything, not just as a professional credential. That curiosity - applying the same analytical rigor to The Simpsons as to CRM integration - is probably a useful thing to have when you are building a product that is essentially applied statistics at the scale of human commerce.
Investors
Lead investor in the $3.8M seed round. Anna Khan and Veronica Orellana representing. CRV portfolio includes companies like DoorDash and Airtable.
S22 batch participant and investor. YC's backing brought the network and the signal that Ciro's thesis was worth testing at scale.
Steven Lee and Beth Turner participating. SV Angel has backed over 700 startups including Twitter, Airbnb, and Stripe in early rounds.
Funding Timeline
Oct 2022 - $3.8M Seed led by CRV. Total funding to date: $3.93M. 43 employees. Annual revenue ~$400K and growing.
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