About
I started a company, served as CTO, grew a team to 35, and eventually walked out of that team. I’ve failed more than I’ve succeeded. These days I’m back to writing code, and I write about those failures here.
What I believe
- Discovery over delivery, outcome over input. Process matters, but process gets judged by whether it ends in a win.
- Cynicism is the worst stance. You see what you know, and you see what you’re trying to learn.
- Don’t judge. Be curious.
- There’s no universal law that runs through life. Everyone has their own path.
What I’m doing now
I stepped down as CTO and went back to writing code. With my partner Ellie, I’m building a small product and experimenting with AI agent workflows. I publish 1–2 posts a week, sometimes about organizations, sometimes about code, sometimes just about my own failures.
These posts represent me best
- Four Years at IHFB: A Retrospective — Growing a team from 3 to 35 and eventually leaving. This is the starting point.
- How a 15-Year CTO Vibe-Codes — Why I stepped down as CTO and went back to writing code.
- No Future for the Org That Doesn’t Win — The starting point of my view on organizations.
- Installing Claude Code Across Your Org Doesn’t Make It AX — A paradox about org transformation in the AI era.
- Reading The Score Takes Care of Itself: On Leadership — A record of my own failures, surfaced by Bill Walsh’s book.
Background
I’ve cycled through 0→1 product building and team building. I haven’t bounced through many teams, but I’ve passed through a few important cycles deeply.
- Loopetto — Co-Founder & Indie Hacker (2025–present). Product experiments for small teams.
- IHFB — CTO / R&D leadership (2021–2025). Built the org from 3 to 35.
- Todait Inc. — Founder & CEO (2015–2021). A study planner. Wound down the company.
Technically I work mostly in Go, PostgreSQL, and AI agent workflows, and I prefer simple, fast, lightweight architecture.
I love content too. I once wanted to be a storyteller, and I still get easily moved by good narrative. I follow F1 race by race, and I’m writing an IT fiction series (Korean only) set in Pangyo (the Korean equivalent of Silicon Valley).
Contact
I post first on Threads when a new piece goes up. Especially happy to talk product, writing, organizations, or AI workflow.
Focus areas
- AI coding
- AI agents
- startup product development
- retrospectives
- team building
- leadership
- Go
- iOS
Recent posts
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Books I Read in Q1 2026
Notes on the 10 books I read in Q1 2026: Stoner, The Obstacle Is the Way, Meditations, Source Code: My Beginnings, Bird That Drinks Blood, the second Krafton Way book, Lost and Founder, The Score Takes Care of Itself, Formula One, and Principles.
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Reading 'The Score Takes Care of Itself': On Leadership
Notes on Bill Walsh's leadership book 'The Score Takes Care of Itself.' The good-talent-bad-attitude equation, his declaration that teaching is the very definition of leadership, and the upward leadership chapter. The three-time Super Bowl winning coach's principles, read against my own failures.
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The Moment You Spin Up an AX Team, You've Already Lost
The paradox of setting up an AX task force. MIT NANDA found the successful 5% weren't led by central AI labs but by line managers on the ground. What I learned from going from consultant to CTO. The first principle of organizational AX isn't tools — it's people and the organization.
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When Package Install Becomes a Hack: Why Zero Dependency Matters
In March 2026, the litellm and axios supply-chain attacks hit back-to-back. I trace ten years of dependencies turning from convenience to trust to risk, and use code to show why zero-dependency design is survival, not minimalism.
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AI Native Engineer: Taste Built on Principles
Being good with AI tools doesn't make you an AI Native Engineer. Taste without principles is guesswork; principles without taste stay academic. After hitting the wall in iOS, getting blindsided as a Maker, and falling into the sorcerer's apprentice trap, I came to one conclusion: an AI-era engineer's identity isn't the toolkit, it's taste built on principles.
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Installing Claude Code Across Your Org Doesn't Make It AX
Rolling out an AI tool company-wide and going through an AX (AI Transformation) are two completely different things. Real AX starts when you redesign roles, KPIs, pipelines, and governance, not when you bolt AI onto a functional org.