Julian Shapiro is a Canadian-born entrepreneur, deeptech seed investor, and prolific writer who built a career that spans open-source animation engines, growth marketing agencies, and a Y Combinator-backed startup. He founded Demand Curve, the largest growth marketing education platform for startups, and now runs Julian.capital, a deeptech seed fund writing $500K-$2M checks into robotics, chips, energy, medtech, and biotech. His free handbooks at julian.com - covering writing, startups, fitness, and audio - are read by over a million people annually. He co-hosts the Brains Podcast with Courtland Allen and was previously VP of Marketing at Webflow.
Willow is a San Francisco-based AI voice dictation startup that replaces the keyboard with voice input across any app. Built by two Stanford dropouts, the product delivers sub-500ms latency, 40%+ higher accuracy than built-in dictation tools, and context-aware transcription that handles technical jargon and proper nouns. Backed by Y Combinator and a $4.5M seed round, Willow targets knowledge workers - engineers, managers, sales teams - helping them type 4x faster by speaking naturally. Enterprise customers include Uber, Gusto, Canva, and GitHub.
YouLearn is an AI-powered personalized tutoring platform built by students, for students. Founded by three college friends frustrated with outdated lecture videos and generic AI tools, YouLearn transforms any learning material - PDFs, YouTube videos, lecture slides, even photos - into concise notes, adaptive quizzes, and an interactive AI tutor. With 2M+ users globally, $770K ARR, and backing from Y Combinator's Spring 2025 batch, YouLearn is building what they call a modern-day Aristotle: a lifelong AI tutor that grows alongside each student.
Zalos builds computer agents that automate repetitive finance operations - from reconciliation to accounts payable - without replacing existing systems. Instead of API integrations, its agents learn directly from screen recordings and then log into ERPs like NetSuite, SAP, and Sage the same way a human would, handling 2FA, navigating screens, and maintaining full audit trails. A Y Combinator Fall 2025 company, Zalos raised $3.6M seed to put invisible finance workers inside the software CFOs already use.
Zarna is building the first cohort of AI associates for private capital - autonomous agents that plug directly into a firm's data and work like a deal team that never sleeps. Founded by four UC Berkeley alumni who were previously forward-deployed engineers at AEA Investors, Zarna automates the grunt work of private equity: tearing down CIMs, building LBO models, drafting IC memos, updating CRMs, and surfacing warm introductions. Backed by Y Combinator (F25), the platform recovers ~80 hours per week for 15-person deal teams and promises full ROI in under 90 days.
Zero is an AI-native email client built from scratch to put artificial intelligence at the center of how people read, write, and manage email. Founded in 2025 by Nizar Abi Zaher and Adam Wazzan, Zero went through Y Combinator's X25 batch and raised $2M from 1984 Ventures, Pioneer Fund, and YC. The product lives at 0.email and promises to cut the time knowledge workers spend on email by 70% through smart prioritization, thread summarization, AI-drafted replies, and conversational inbox search. With over 10,000 GitHub stars on its open-source repo, Zero is one of the fastest-growing AI email projects of 2025.
Zephyr Fusion is building the first in-orbit fusion power source - a compact, megawatt-class reactor designed to run in the vacuum of space. Founded by two physicists who met in grad school operating a spherical tokamak, the San Diego-based startup uses a levitated dipole magnetic confinement approach with high-temperature superconductors. Their bet: space makes fusion easier, not harder. With launch costs down 10x and mass-produced HTS tapes providing 10x more field per kilogram, Zephyr Fusion aims to power the industrial revolution that humanity is about to have off-planet.
ZeroSettle is a drop-in SDK that lets mobile app developers skip Apple's 30% cut on in-app purchases by switching users to direct billing - charging just 5% + $0.50 per transaction instead. Built by two former Apple software engineers and backed by Y Combinator (W26), ZeroSettle arrived at the exact moment the Epic v. Apple ruling cracked open a $150B+ market. Setup takes 15 minutes, and developers get instant Stripe payouts, built-in tax compliance across 190+ countries, and smart conversion flows to migrate existing subscribers - all without touching App Store rules.
Zymbly is a UK-based AI startup that builds voice-first copilots for aircraft maintenance technicians - automating troubleshooting, parts lookup, and compliance documentation so mechanics can spend their time fixing planes instead of drowning in paperwork. Backed by Y Combinator (W26) and built by a team with deep roots in aviation and enterprise AI, Zymbly targets an industry facing a global shortage of 43,000 technicians and a maintenance capacity crisis.