How I Found a Winning Idea After 8 Pivots | Pensive, Yoon
In a Nutshell
Yoon, CEO of Pensive—an AI platform slashing instructor grading time by 60-90% and recently raising $6.8M seed—shares his journey from a thyroid cancer diagnosis at 18, inspiring a 10-year "if I die tomorrow" decision framework, to 8 startup pivots before founder-market fit in AI-powered education. Using the "Eeky Guy" framework (love it, good at it, world needs it, get paid), he validated Pensive via resourceful outreach to professors at Berkeley, Columbia, and UCLA, targeting repetitive grading pains in massive CS classes. He urges young founders to boldly tackle humanity-empowering AI challenges amid rapid uncertainty, building unique paths through decisive action for outsized impact.
These notes were generated by AI and may contain inaccuracies.
Right after graduating from high school, went to a local hospital that found a 1 cm tumor in thyroid, confirmed as thyroid cancer. This changed perspective on viewing the world. Core decision-making approach: if I were to die in 10 years, would I be doing what I'm doing now? A 10-year timeline eliminates side tracks and excuses clouding vision and life goals.
Helping AI automate grunt work is meaningful, but not enough founders are using AI to empower humanity. If we cannot empower humanity with AI, we lose purpose; no meaning for humanity to evolve as AI gets smarter. Urges smart young founders to pursue bolder, harder problems, act on them, be bolder, make bold bets for surprisingly bigger returns.
Hi, I'm Yoon, CEO and co-founder of Pensive. Pensive is an AI learning platform that helps instructors grade much faster, reducing grading time by 60-90% without losing accuracy. Recently raised $6.8 million seed round led by Mayfield Fund, followed by Antler Fund, Reach Capital, Base Ventures, Sequoia Capital, and A6 Scouts. Aims to reimagine higher education to be more affordable, personalized, and accessible using AI.
Born on a small island in South Korea, where university attended matters greatly for societal success. In elementary and middle school, studied alone until 2:00 a.m. to compete. At 14, questioned the stress and hours: what am I getting? Read books across subjects seeking answers to why study so hard and for what.
Discovered founders like Steve Jobs and Bill Gates who created new things with global impact; fascinated and wanted to be like them. Dad's reaction: founders like them are geniuses, you don't have the DNA; just study hard, get into good Korean university, become a lawyer. Agrees founders are special but believed capable of becoming one.
Instead of obeying, thought if could turn $100 saved allowance into $200, dad would believe. Went to Korean street market to sell backpacks in freezing cold; failed to sell any for 2 hours, hands frozen. Pivoted to unique strategy: targeted people who seemed like they had a son like him, pitched not as backpack but as a memory—every time worn, think of story of kid selling in freezing winter for courage despite challenges. Sold first backpack that way.
Realized wanted to found long-lasting company creating durable, new things. Decided to be technical, learn hard skills to build software and products for generational global company.
Came to Berkeley, founded first company after one month. Before Pensive, pivoted eight times in a year. Did market research, identified pain points, wrote hypotheses, validated, built scalable small MVPs, talked to users—all per YC advice. Missing: founder-market fit. Am I founder who can pursue this for next 10 years? Without purpose and mission, hard to wake up excited daily.
Reiterates 10-year death framework from thyroid cancer diagnosis at 18 (most curable cancer, but caused family chaos and shock). Possibility of dying in next 5 years shifted perspective: with only 10 years, eliminates credentials chase like master's or PhD before startup.
Eeky Guy framework for choices: do what you love, you're good at, world needs, and can get paid for.
Three major problem sectors cared about and world needs: learning/education, energy/climate change, healthcare/curing cancer.
Good at learning/education: prior work at Grid on machine learning/language models in education; fast-growing startup (grew 20x) taught operations, educational startup mindfulness, gained expertise/domain knowledge as research scientist.
Learning and education fits: love it, good at it, can get paid, world needs now.
Investors surprised by quick execution; edtech, especially selling to colleges, freaks them out—traditionally hardest sector for venture-scalable outcomes in higher ed. Team's execution speed stood out given sector's slowness.
At Berkeley, first class CS61A had 2,000 students in largest auditorium; couldn't see professor's face, professors wouldn't remember name. Lacked resources of MIT, Stanford, Carnegie Mellon; unique challenges.
As instructor/tutor, grading 1,000+ submissions daily: after 500, mechanically circling rubrics 1,000 times. Biggest pain point Pensive eliminates: remove routine, mechanical, repetitive grading so faculties/TAs focus on feedback, more office hours, group tutoring.
Call with Columbia professor Tony Deer: day before, created Figma mockup landing page for AI grading (not deployed), showed after 30-min AI tutor demo. In last 5 minutes: showed AI grader landing page, asked if he'd use. Response: AI tutor cool, but AI grader is what I need most; want to try it right away. Aha moment: grading is pain point for many instructors. Validated stronger meeting more.
Core strength: resourcefulness—understanding resources around, reaching out even if stretch.
Emailed UCLA faculties: visiting campus, if interested in tool for faster grading without losing accuracy, book Calendly. If full day booked, flew in to meet all day; if not, skipped campus. Efficiently validated needs per campus, flew to meet 10:1, built relationships. Got first 10 colleges by flying nationwide, meeting faculties in person, persuading to use Pensive.
2026 goal: licensed in hundreds of universities nationwide. Then direct-to-consumer/students, become ideal AI-native learning institution.
Future: AI-native schools as socialization environments; knowledge/learning via intimate 1:1 AI tutors at home/different settings. Pensive best positioned: knows how to build best AI teaching assistants for long-horizon learning.
New generation raised never smarter than ChatGPT from birth to death. Founding Pensive for this. Reiterates: empower humanity with AI or lose purpose.
Urges young/smart founders to pursue bolder problems empowering humanity with AI.
Most important quality to learn/survive/make impact: ability to make good decisions in uncertain environments. Things change quickly; no one knows answers, contexts differ—can't rely on others.
Personal motto: every event feels like destiny if you know your path.
Practice conscious decisions in uncertainty (without full info): step forward on own path. Accumulating conscious choices forms unique path no one, including AI, can replicate. Creates uniqueness society respects.
Act on it, be bolder, make bold bets for bigger returns.
Keep EO in your library
Save the videos and channels worth coming back to, and find them again in one place.
