ValleyJin · Medium Medium · Daejeon, Korea

Jin Sam Cho

At the intersection of AI, blockchain, and the physical world.

Coding + Business. I ship LLM systems on the cloud, build blockchain infrastructure, and teach machines about the physical world — then write about what I learn.

github/ValleyJin x/@ValleyJin → writing

Writing

all posts →

2026.09.19 Relaunching this site as a working journalA quieter, editorial home for notes on AI, blockchain, and building — with a homepage t... Meta
2026.09.10 Serving open LLMs on Cloud Run with vLLMNotes on getting throughput up and cost down when you serve your own models instead of ... AI
2026.08.28 What an L2 actually has to get rightRollups are easy to describe and hard to operate. A short list of the parts that decide... Blockchain
2026.08.15 Giving robots a usable model of the worldPerception tells a robot what it sees. Knowledge tells it what that means. The gap betw... Physical AI

Launched

Kyopo AI Solo · designed & built

Multilingual batch document translation into 50+ languages.

Designed and built end-to-end — Excel, Word, HWPX, PowerPoint, PDF, and Google Workspace files translated in one pass. Preserves tables and layout, caching cuts cost up to 80%, with glossary control and TTS in 40+ languages.

kyopo.ai →

Currently building

all repos ↗

HTML ValleyJin.github.io · ★ 1
ValleyJin's blog
Java spring-react-ioc-crud-study · ★ 1
강의용
TypeScript react_basic · ★ 1
강의용
JavaScript react_homework
강의용
CSS tailwind_shadcn
강의용

Focus

01 AI · LLM & Cloud

Serving open LLMs at scale — vLLM on Google Cloud Run, inference optimization, agentic pipelines.

02 Blockchain

Ethereum & OP-stack L2 infrastructure with the Tokamak Network ecosystem.

03 Physical AI

Ontology-based reasoning for embodied agents and robotics (KnowRob).

04 Full-stack

Product engineering across React · TypeScript front-ends and Spring · Java services.