I'm Charles,a Technical Founder and Product Builder

Revision History is a Chrome extension that shows teachers how a student's work was actually written — replaying the document from first keystroke to final draft, rather than guessing at AI use with a detection score.

Built two new products from zero on a 3-person team: slide replay for Google Slides, and Byline, a student-facing AI tool built so students can use AI openly and teachers can see how. Designed the architecture, reverse-engineered undocumented data structures, and built the data pipelines behind them. Used by 200,000+ teachers.

Greeni helps companies measure and report their environmental impact.

Rebuilt the frontend on a modular architecture, turning a codebase the team struggled to change into one they could iterate on quickly, and introduced reusable patterns and AI-assisted workflows so a small team could validate product changes faster.

Voy lets travelers book trips by talking to an AI agent instead of filling out search forms.

Built the mobile app end to end — conversational UI, backend, and agent integrations — on a React Native and Next.js monorepo with a custom design system.

A leading vegetable trading company in Europe manually processed daily price lists from suppliers in various formats (PDFs, emails, images), resulting in inefficiencies and high operational costs.

I independently designed the architecture and built an OCR-powered system to automate parsing, processing, and structuring data for direct business use, eliminating manual entry inefficiencies.

Hokkaido Track, a luxury ski resort in Japan, required a contactless solution to uphold its high-end service quality as guests avoided direct interaction during the pandemic.

I transformed hotel operation manuals into automated digital workflows, streamlining guest requests and staff coordination. I designed the entire system architecture, UX and UI, and built an interactive Figma prototype for guest and operator apps.

Taiwan-New Beef Noodle, a 40+ year-old brand in Taiwan had to pivot during the pandemic lockdown as in-person dining was no longer possible.

I set up an e-commerce platform to sell ready-to-cook products, enabling online orders with seamless inventory, logistics, and payment integration. This allowed the restaurant to continue operations and reach new customers.