Hi, I'm Ken.
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About

I'm a hands-on engineering leader based in Seoul, open to relocating to Japan or the US. My career spans US consumer brands (Nike, Barnes & Noble, Livestream) and startups — most recently as CTO of Wired Company, where I built and led a ~20-person platform team from zero, hiring across engineering, product, QA, and design.

I stay deliberately close to the code: I architect modern React/TypeScript systems and integrate LLMs, RAG, and multimodal pipelines into real products. Through Vanilla Coding and now Pi Lab, I've trained hundreds of working engineers to ship production software — including the AI systems behind this very site.

• 12+years engineering
• ~20person team led as CTO
• ~400engineers trained
• 94%graduate placement

Experience

1. 2026 — Present
   Pi Lab Inc. Seoul, Korea

   Founder & Lead Instructor

   • Founded an AI engineering bootcamp for practicing developers, focused on shipping production AI systems — 100% completion across the first two cohorts.
   • Designed the curriculum from real production concerns: document chunking, embeddings, vector-DB indexing, hybrid retrieval (BM25 + semantic), reranking, and hallucination control with grounded citations.
   • Built an evaluation discipline into every RAG project — golden sets, retrieval accuracy, and answer-faithfulness scoring — plus multimodal pipelines (STT, frame extraction, cross-modal embeddings).
   • Live-code reference implementations and ship deployments hardened for cost and latency (caching, streaming, observability). This site runs on the same RAG stack I teach.

   TypeScript, Next.js, OpenAI / Claude APIs, Embeddings, Vector DB, Hybrid Search, Reranking, Multimodal (STT / vision)
2. 2021 — 2023
   Wired Company Seoul, Korea

   Chief Technology Officer

   • Built and led a ~20-person platform team from the ground up, personally hiring every member across engineering, product, QA, and design.
   • Led all engineering for Kemi, a SaaS commerce platform for creators, from early development to public launch.
   • Architected the client-side application — a Next.js / React frontend in TypeScript with Tailwind CSS — backed by a GraphQL API layer on Node.js, deployed on AWS.
   • Established the team’s engineering processes, code-review culture, automated testing, and delivery workflow so the org could scale sustainably, while staying hands-on in the codebase.

   React, Next.js, TypeScript, Tailwind CSS, Node.js, GraphQL, AWS, Testing / CI
3. 2017 — 2025
   Vanilla Coding Seoul, Korea

   Founder & Lead Instructor

   • Ran a full-stack JavaScript engineering school for 8 years, graduating ~400 engineers with a 94% job-placement rate.
   • ~10% of graduates now work at top Korean tech companies including Naver, Kakao, Daangn, and Toss.
   • Designed and taught a production-oriented, full-stack curriculum: core CS (data structures & algorithms), modern frontend (React, state management), backend (Node.js, Express, REST), databases, and infrastructure/deployment.
   • Mentored engineers one-on-one in system design, code review, and Git collaboration — built around how engineers actually work on teams.
4. 2016 — 2017
   And Co acq. by Fiverr Remote

   Lead Frontend Engineer (Freelance)

   • The only frontend engineer in a fast-moving 15-person startup building tools that help freelancers manage clients, contracts, invoicing, and projects (And Co was later acquired by Fiverr).
   • Single-handedly owned three production surfaces end to end: the internal operations dashboard, the client-facing web application, and a cross-platform desktop app built with Electron.
   • Modernized a codebase originally written by non-frontend engineers, introducing a maintainable Angular/React component architecture and a consistent Stylus styling system.
   • Owned all client-side architecture decisions and the Grunt/ES2015 build pipeline, shipping features rapidly as the sole frontend specialist on the team.

   Angular, React, Electron, Stylus, Grunt, ES2015
5. 2016
   Nike Beaverton, OR

   Lead Frontend Engineer (Contract)

   • Joined a greenfield agile team to re-architect Nike’s global content management system into a modern Aurelia single-page application, publishing photos, video, copy, and styling daily to consumer-facing digital products across markets.
   • Designed a modular client-side architecture and a reusable component library and Stylus design system that standardized UI platform-wide and measurably accelerated feature delivery.
   • Engineered the localization/i18n layer so a single system could publish editorial content to multiple global markets and languages.
   • Tuned front-end performance and the Gulp/ES2015 build-and-asset pipeline for fast, repeatable releases; set frontend conventions, mentored junior developers, and was offered a full-time frontend lead role.

   Aurelia (SPA), ES2015, Stylus, Gulp, Component Library, i18n / localization
6. 2014 — 2015
   Barnes & Noble New York, NY

   JavaScript Engineer

   • Built and maintained a large-scale NOOK e-textbook reader for Windows 8 and web, architected with Knockout.js (MVVM) and a mix of object-oriented and functional patterns for long-term maintainability.
   • Engineered in-book full-text search and a rich annotation system — highlighting, notes, and bookmarks — backed by reactive client-side state across very large documents.
   • Optimized rendering, pagination, and memory usage to keep the reader fluid and responsive on resource-constrained Windows 8 devices.
   • Shipped regular releases in an agile cycle and systematically drove down defects; recognized as a top-performing engineer of the year.

   Knockout.js (MVVM), Jade, Stylus, ES2015, Grunt
7. 2014
   Livestream acq. by Vimeo New York, NY

   Software Engineer

   • Built and scaled backend RESTful APIs (Node.js / Express) for a live-streaming platform that sustained up to 15,000 requests/sec during peak live events.
   • Implemented real-time delivery with Socket.io to fan out low-latency live updates to large numbers of concurrent viewers.
   • Used Redis for caching and pub/sub to absorb peak read load and shield MySQL, improving API latency and reliability under heavy concurrency.
   • Authored reusable internal JavaScript libraries that standardized API patterns and sped up feature delivery across the team.

   Node.js, Express, Socket.io, Redis (cache / pub-sub), MySQL