Junghyun Nam (남정현)

(한국어 버전 보기)

E-mail: [email protected]
Telegram: @cr0sh
GitHub: @cr0sh
LinkedIn: 남정현
Blog: blog.cro.sh

Last updated: 2023-05-15

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I'm living in Seoul, Korea.

For now I'm not actively searching jobs but inbound job offers are appreciated.

I'm on an alternative supplementary service as skilled industrial personnel, ending on July 30th, 2023. Hence I can only work full-time on designated companies non-remotely by the Office of Military Manpower Administration of Korea.

저는 현재 보충역 산업기능요원으로 복무 중이며 예상 소집해제일은 2023년 7월 30일입니다.

Education

Seoul National University 2019.03 ~ leave in absense

Currently on undergraduate courses majoring in Computer Science & Engineering.

  • GPA: 3.9/4.3 (not finalized)
  • Credits: 45/41 (not finalized)

Also double-majoring in Statistics.

Sejong Science High School 2016.03 ~ 2019.02

Work Experiences

Hyperithm (https://hyperithm.com) 2021.08 ~ current

Hyperithm is a leading digital assets manager in Asia, based on Japan and Korea.

  • Head of Infrastructure
  • Maintaining the overall cloud infrastructure based on AWS and GCP.
  • Developed and maintaining a HFT-optimized cryptocurrency exchanges data feed.
    • Keywords: Asynchronous Programming, Rust, Tokio, HTTP, WebSocket.
  • Designed & managed development of a trading strategy management infrastructure.
    • (think stripped-down version of ECS or EKS with some internal niche feature demands).
    • Keywords: Rust, AWS CloudFormation, AWS S3
  • Developed & maintaining an DevOps toolkit for AWS infrastructures, featuring seamless 1Password integration with AWS credentials management.

Research Intern at CARES Lab 2021.03.26 ~ 2021.06.30

Started as SNU UROP(undergraduate research opportunities program) on February, then switched to paid intern on March.

Worked on RustFTL, a (partial) Rust port of the FEMU SSD emulator.

Rewrote FTL(flash translation layer) part of FEMU into Rust and reported about use of Rust on embedded systems focusing on safety, performace impact, and idiomacy of Rust code on FTL structures.

The final report and documentation were constructed with mdBook and rustdoc.

Engineering Intern at CN.AI 2020.08.01 ~ 2020.08.28

Constructed data pipeline for deep audio classifier with PyO3 and HDF5 to boost training speed.

Developed a demo website with StyleGAN2 which synthesizes 'median face' from given two facial images.

  • The model is pretrained with FFHQ dataset on TensorFlow, and communicates with backend with a simple TCP server.
  • The backend is written in Golang with its standard net/http module and the Gorilla web toolkit.
  • The frontend is based on React.

Skills

Programming Languages

  • Rust(primary): Tokio and related async ecosystem packages, aws-sdk-rust
  • Golang: net/http, Bolt(embedded KV store)
  • C
  • TypeScript: Mostly React
  • Python: Tkinter, requests, Bolt(Slack SDK)
  • Other misc. languages w/ basic experiences: C++, Java(JVM, Android), Dart(pre-2, Flutter), OCaml

DevOps

Have managed several on-premise solutions such as Jenkins, a security management platform (private)

Experiences:

  • CI/CD pipeline with AWS EC2, EC2 Image Builder, ECR, etc.
  • Layer-7 HTTP proxy clusters with AWS EC2 Launch Template, ECS, ECR, etc.
  • Fine-grained access control of EC2 instances with AWS Systems Manager Session Manager and IAM.

Linux & Systems Programming

Experiences:

  • Embedded Linux development with Raspberry Pi(1B+, Zero W, 3B+) and Buildroot.
  • Kernel hacking including implementing custom syscalls and task schedulers.

Blockchain & DeFi

Knowledges:

  • General consensus mechanisms, e.g. Proof-of-Work, (naïve) Proof-of-Stake and their variants like Proof-of-History, Byzantine Fault Tolerance, etc.
  • How decentralized finance works and their sub-categories: money markets, DEXes, yield aggregators, stablecoins, etc.
  • Cross-chain/multi-chain/layer-2 ecosystems: Wormhole, Cosmos, Polkadot, Arbitrum, ZKSync, etc.
  • Intuitive understanding of zero-knowledge proofs and their applications on blockchains.
  • Invested on some of projects mentioned above.
    • Track record? Please don't ask.

Nerf Rust, Serde, Tokio, Tower, Hyper, HTTP Link to the GitHub repository

A HTTP request framework with tower-rs intergration.

This is an experiment about cryptocurrency exchanges API into composable tower::Layers, achieving:

  • Switchable HTTP client backends.
  • Configurable rate limits (provided by tower-rs).
  • Multiplexed HTTP clients (provided by tower-rs).
  • Mock testing paired with axum.
  • Automatic throttling based on API responses with remaining rate limits (TODO).

WASynth(WIP) Rust, WebAssembly Link to the GitHub repository

Universal, language-agnostic instrumentation with WebAssembly.

Features:

  • A standalone WebAssembly parser/generator implementation.
  • Enter/leave hook injection into WASM binary functions.
  • cargo fuzz-powered fuzzing.

Talks

Introduction to NIZK Proofs

https://blog.cro.sh/slides/introduction-to-nizk-proofs-20220307.pdf

Rust 비동기 프로그래밍 (Asynchronous Rust Programming)

https://blog.cro.sh/slides/async-rust-programming-20220801-redistributable.pdf

Languages

Acknowledgement

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