CTO building developer-first products for mobile retention, customer engagement, and agent workflows.
- Clix — AI-native mobile retention and customer engagement platform for developers
- OpenClix — open, agent-friendly messaging stack with a vendoring-first distribution model
- Agent infrastructure — MCP, A2A, docs search, and tooling for AI-assisted workflows
Software engineer and product-minded CTO based in Seoul / SF Bay Area.
Over the last 15 years, I've worked across experimentation platforms, CRM marketing automation, mobile growth tooling, and developer infrastructure. I like products that make complex systems feel simple for developers.
Named after Werner Herzog's 1982 film Fitzcarraldo — a story of a man who hauls a 320-ton steamship over a mountain in the Amazon jungle to build an opera house. I stumbled upon the film by chance and watched it young, so it was a bit hard to follow, but the sheer image of dragging that ship up the mountain — filmed without any special effects — never left me. When I needed an ID for games, email, and other accounts, fitzcarraldo felt distinctive enough — but it was taken more often than expected, so I slightly twisted it into pitzcarraldo. I've used it everywhere since, including Gmail, GitHub, and Twitter. The name carries the spirit of the film: getting the impossible done, no matter how absurd the odds.
Developer-first AI customer messaging and retention platform — covering mobile engagement, in-app messaging, push & live activity, retention analytics, experimentation, and AI-assisted campaigns.
Open, vendoring-first messaging stack for the agent era.
Built for easier local customization, fewer dependency issues, and better compatibility with AI coding agents.
Exploring MCP servers, A2A interoperability, LLM-ready docs/search, multi-agent workflows, and AI-native DX patterns.
| Period | Role | Company | Highlights |
|---|---|---|---|
| 2025 – | CTO | Clix 🇺🇸 | AI-native mobile engagement, agent infra |
| 2023 – | CTO | Notifly 🇰🇷 | CRM marketing automation, platform engineering |
| 2022 – 2023 | Founder | Livewire 🇰🇷 | Location basesd music venue curation, fullstack engineering |
| 2021 – 2022 | CTO | Your.gg 🇰🇷 | Analytics, experimentation, infra |
| 2020 – 2021 | Tech Lead | Banksalad 🇰🇷 | Backend foundation, data-intensive systems |
| 2013 – 2020 | Principal Software Engineer | Coupang 🇰🇷🇺🇸 | Experimentation platform, large-scale systems |
| 2010 – 2013 | Software Engineer | NAVER 🇰🇷 | Started as intern, built NAVER TV from scratch, recommendation engine |
AI-native mobile retention and customer engagement platform for developers.
SDKs · messaging orchestration · observability · AI-assisted campaigns · MCP server for docs and agent workflows
Includes OpenClix — an open, vendoring-first distribution of the messaging stack for agent-era development.
CRM marketing automation platform.
Multi-channel campaign orchestration · performance optimization · platform engineering at Grey Box.
Experimentation Platform @ Coupang
A/B testing infrastructure, near real-time experiment processing, and large-scale platform modernization from monolith to microservices.
NAVER TV @ NAVER
Built the video platform from scratch as an intern-turned-engineer. Recommendation engine, distributed video infrastructure.
- reduxible — React + Redux development toolkit
- universal-fetch — Isomorphic Fetch API for browser and server environments
- Code is writing. It should be clear to the next reader — whether human or agent
- Ideas are cheap, launching is harder, and retention is hardest. Product, engineering, and distribution are the same conversation
- Engineers exist to move the business forward. Pragmatic architecture over fashionable complexity
- Sharp razors dull fast; a well-maintained axe lasts decades. Sustainable transitions matter more than early peaks
- Constraints sharpen decisions. A failed product you shipped teaches more than a perfect one you planned
- Don't assume you understand — ask. Over-communication beats interpretation, especially across different backgrounds and experiences
- Make complex systems feel simple. DX is not polish — it's core product quality
AI-native SaaS, mobile retention infrastructure, agent interoperability (MCP / Skills, A2A), vendoring-first developer tools, OSS-to-cloud strategy, and fast iteration loops for startup teams.
Building products for developers, mobile apps, and the agent-native future.