Backend and EVM contract developer at Seoul Labs Inc., based in Seoul.
AI made prototypes cheap. It did not make the part after cheap — the migration that cannot take the table offline, the settlement job that must not pay twice, the capacity plan that decides whether the monthly bill is $200 or $2,000. That is the part I work on. I take someone's idea past the proof of concept into something that runs in production, and then I keep it running.
- Protocol negotiation with a hardware vendor — Agreed the mining protocol directly with a NASDAQ-listed ASIC manufacturer, then designed, built, and now operate the XPhere pool as its sole engineer.
- Concurrency that makes the node scale — 3,000 concurrent ASIC connections per node: write-behind batch buffering cut Redis round-trips ~100x, time-bucketed counters made hashrate reads O(1), lock-free node-ID sharding removed write contention.
- Migrations with the lights on — Repartitioned a 2.58B-row (60GB) production table with zero downtime: shadow table, online backfill, atomic rename swap under a sub-one-second lock.
- Money that survives failure — Config-gated single-leader execution, idempotent settlement keys, atomic pre-deduct transactions. A crash or a replay cannot pay a miner twice.
- Infrastructure sized to real traffic — I calculate the load a system will actually see and build for that number. Bounded retention with verified BigQuery archival holds a +7.8GB/day write path flat instead of buying disk; the cheapest architecture is usually the one nobody over-engineered.
| Award | Project | Stack |
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3rd Place
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Monder — Tinder's swipe UX turned into an O/X price call. Chainlink Data Streams pushes a new ETH / LINK / BTC price every five seconds; a wrong call or a timeout eliminates you, and the last player standing takes the pool. Built in a six-hour hackathon. |
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Best Technical Implementation
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Tusk — A consent-based hiring platform. Résumés are encrypted with Seal and stored on Walrus, access policies live on Sui, and a recruiter sees the full document only after the candidate approves — on chain. I built the backend: a 768-dimension Gemini embedding pipeline with pgvector cosine search, layered API → Service → Repository. One of three projects named for technical implementation out of hundreds of submissions across 27 countries, in the first hackathon to combine Walrus, Seal, and Nautilus. |
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| Project | Description | Stack |
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A mining pool for the XPhere blockchain, built and operated end to end by one engineer. The Stratum server (JSON-RPC over TCP) holds 3,000 concurrent ASIC connections per node; daily settlement is single-leader gated and idempotent, so a crash or replay cannot pay a miner twice. Runs on Prometheus/Grafana with an audit table for operational errors.
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A technical blog built as an architecture exercise, not a template install. Notion is the headless CMS behind five layers with ports and adapters, so the CMS can be swapped without touching business logic — wired through a DI container and covered past 90% in tests. Reading side: ⌘+K fuzzy search, URL-driven tag filtering, RSC streaming.
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| Role | Highlights | Stack |
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Back End / Contract (EVM) Developer
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XPhere Mining Pool — sole engineer; see above.
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Curriculum Developer
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Wrote the React and Next.js curriculum for a commercial coding academy — App Router rendering determinants and caching strategy, Supabase auth, TanStack Query optimistic updates, Tailwind v4 migration, and diagrams for SSR / SSG / ISR. |
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IT Team Lead & Full-Stack Developer
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Led IT and built the platform end to end. Swapped a commercial OCR vendor for OpenAI Vision at ~90% lower cost, moved uploads to S3 presigned URLs, and stood up NestJS on AWS from scratch — EC2/RDS, Nginx, Let's Encrypt, GitHub Actions CI/CD, JWT at the middleware layer. Flutter app on feature-based clean architecture with Riverpod. |
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Full Stack Developer
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Built CelebCard from the ground up — Vue 3 web front, Flutter iOS/Android apps, NestJS backend, and the deployment behind them. Also won Meta's approval for Instagram API access by writing the English technical documentation and demo myself. |
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