Portrait of Dohyun Kim

Hello, I'm Dohyun

I write code for markets I understand as an investor.

GitHubResume (PDF)

  • Software Engineer · Trading systems
  • UE Potsdam, Germany
  • English, Korean

About

I got into markets during military service, then co-founded a small fund and grew it from $20K to $60K.

I found software almost by accident. I joined a team building a crypto exchange as a translator, which led to a job running trading bots at Neonex, and soon to writing them. With no formal background, I learned operating systems and algorithms from online lectures and saved up to study them properly. Today I'm doing a Software Engineering degree in Germany, paid for with money I earned.

Experience

Bitopex Trading

Software Engineer

Jun 2024 — Jun 2026

Remote

Bitopex Trading homepage
  • Built an options backtesting engine (Black–Scholes, Deribit IV) for copy-trading products with $6M+ AUM.
  • Implemented Binance and OKX exchange connectors over REST and WebSocket APIs for real-time trading.
  • Built a FastAPI service feeding backtest stats to risk controls that auto-disable underperforming strategies.
  • Led system design for Rivermatch, a B2B marketplace matching merchants with payment acquirers, and built its MVP CRM in NestJS and Next.js, covering the full deal lifecycle with real-time messaging and notifications.
  • Built the Next.js frontend for HypeRocket, a crypto yield platform with multi-tier referral payouts, in 11 languages (i18next), with Cloudflare caching for DDoS protection.

Python · FastAPI · TypeScript · NestJS · Next.js

Neonex

Software Engineer

Nov 2023 — Jun 2024

Seoul, South Korea

Neonex homepage
  • Designed and implemented Node.js market-making bots using an asymmetric grid strategy, dynamically adjusting bid/ask spreads and volumes to mitigate inventory risk across 20+ spot and 10+ futures instruments.
  • Developed ninjaxt, an open-source NPM library supporting REST and WebSocket APIs for trading.
  • Built a Next.js dashboard for positions and inventory ratios, with CI/CD via Docker and GitHub Actions.

Node.js · TypeScript · Next.js · Docker · GitHub Actions

AlphaPortfolio

Co-founder

Feb 2021 — Mar 2023

Seoul, South Korea

  • Raised $20,000 from private investors and grew the fund to $60,000+, drafting investment and partnership agreements and reporting regularly on performance and strategic adjustments.
  • Built a quantitative strategy for undervalued KOSPI/KOSDAQ small caps using PBR, PER, PSR, EV/EBITDA.

Projects

Crypto Exchange Platform

github.com/dohyunkjuly/crypto-exchange-platform

Screenshot of Crypto Exchange Platform
  • Built an open-source, white-label crypto exchange as Spring Boot microservices over Kafka, with an in-memory matching engine that recovers from crashes via S3 snapshots and command replay.
  • Achieved effectively-once processing over at-least-once delivery using a transactional outbox and idempotent consumers for settlement (MySQL ledger), market data (MongoDB), and real-time WebSocket feeds.
  • Benchmarked ~4,200 orders/s per engine end-to-end including the Kafka publish round trip; shipped copy trading, 7 order types, and an HMAC-signed public REST/WebSocket API.

Java · Spring Boot · Kafka · Next.js

AlphaCrypto

github.com/dohyunkjuly/overfitting

  • Maintain an open-source Python backtester for crypto futures, simulating liquidation, leverage, margin, and slippage.
  • Deployed automated trading strategies with a ~100% annual return (Aug 2023 — Jun 2024).

Python

Education

University of Europe for Applied Sciences

2025 — 2028 (expected)

B.Sc. in Software Engineering · Grade 97.28/100 · Potsdam, Germany

New York University

2017 — 2019

Gallatin School of Individualized Study · New York, USA