Heungsub Lee

[email protected]
Web Sites
Homepage, GitHub Profile, LinkedIn Profile



Programming Languages
Python (expert), Bash, C#, Go, Node.js, C
Back-end Technologies
ØMQ, AWS, Docker, etcd, gevent, Google App Engine, Upstart, Fabric, Linux
Databases or Cache Storages
Couchbase, Redis, PostgreSQL, SQLite, MongoDB
Test Engineering
pytest, GitLab CI, Travis CI
Web Development
Flask, Requests, jQuery, socket.io, HTML5/CSS3, Nginx, Gunicorn
Vim, Visual Studio, Git, Plastic SCM, Mercurial, Visio, VirtualBox

Work Experience

Game Server Technical Director
What! Studio in Nexon, 2013–
Developing Durango, a seamless open world MMORPG.

Designing and implementing the architecture of a flexible distributed MMORPG server to achieve high-availability of the game service. Building a development process and pipelines for the studio. Leading game server engineers and DevOps engineers.

Using Python, C#, C, Cython, ØMQ, MsgPack, Couchbase, etcd, Redis, PostgreSQL, Unity3D, Git, PlasticSCM, Fabric, Docker, Ubuntu, and AWS.

Game Development Engineer
Team Lupin in Nexon, 2011–2013
Developed and published mobile and Web series of KartRider, a synchronous multiplayer casual racing game.

Designed and implemented a distributed game server architecture for synchronous multiplayer games for the KartRider Dash and KartRider Coin Rush series.

Researched various rating systems such as Elo, Glicko, and TrueSkill. Implemented a simple matchmaker for 4v4 or free-for-all racing games.

Used Python, Redis as a message broker, Couchbase, MongoDB, Unity3D, Mercurial, Ubuntu, and AWS.

Full Stack Web Developer
Npine, 2008–2011
Supplies stock images for business on Iclickart.

Developed a web server framework adapting the MVC pattern by PHP5. Made and maintained web sites where provide stock images including Iclickart by the own framework. Maintained physical Linux machines in a data center.

Led the software engineering team.

Front-end Web Developer
Lunant, 2008–2011
Served VLAAH, a social network service for discovering, sharing, and utilizing opinions.

Designed and implemented the UI/UX for VLAAH by PHP5, JavaScript with MooTools, and Python.

Developed jDoctest, which tests JavaScript examples in doc comments, by JavaScript.

Open Source Experience

Profiling, 2014–
An interactive profiler for Python inspired by the Unity3D profiler.

Developed to find bottlenecks in the Durango server by Python and C. Designed a handy interactive TUI like htop by Urwid.

On GitHub, 2400+ people stared this project. Also it was the 3rd daily trending repository at Sep 22, 2014.

TrueSkill, 2012–
A Python implementation of TrueSkillTM which is a rating algorithm for Xbox Live.
Implemented TrueSkillTM by Python with simple API to learn and share the smart algorithm.
Hangulize, 2010–
Automatically transcribes a non-Korean word into Hangul.

Implemented the library to realize Brian Jongseong Park’s idea by Python and complex regular expressions.

Designed and implemented the Web service and RESTful API by Flask on Google App Engine. Many professional Korean translators visit here to translate undocumented proper nouns.

  • Zeronimo – A distributed RPC system based on ØMQ
  • Lets – Several utilities for gevent
  • Energy – Energy system for social games
  • Flask-AutoIndex – mod_autoindex for Flask
  • SUBLEERUNKER – A simple prody game of SUBERUNKER
  • Me2virus – An XSS attack on Me2day, a social network service. When a user looks an infected post, a new infected post was written on the user’s wall.
Babel#427, #488; couchbase-python-client#32, #33, #35; etcd#4320; Flask-0.10.1; gevent#608; jQuery-1.4.3; node-irc#3; pytest-rerunfailures#47; PyZMQ#951.

Invited Talks


Computer Software, Kwangwoon University, 2008 – Completed the first year and left in mid course.