Welcome To My Blog

1. Working Career

I’m in my 5th year working as a Data Scientist, and also have experience in Backend Engineering. I team that services Map application. I specialize in:

  1. Rust/C++ backend engineering
    • As a junior I was in charge of the backend server that calculated the Walkpath.
    • Was in charge of route searching part of our Map Server(1 year), improving subway route search time by 200%,
    • Refactored the whole Maps Rust Backend Server which was using libraries that were deprecated 3 years ago, improving 99% latency by 10%(3000ms -> 2700ms) and Max latency by 85%(9600ms -> 5200ms)
    • Tryed hard to improve our team’s working culture:
      1. I was the first to add Team Coding Convention for the backend engine
      2. I doubled our backend server’s number of tests
      3. Provided documentation for the backend server’s hard-to-understand legacy parts as I refactored it.
  2. Machine learning / Deep Learning(Spark, Pandas, Polars, Tensorflow)

    • In charge of building the first AI model for predicting the arrival time of a given car route.
    • The data pipeline was built using spark, and the model was made in pandas/tensorflow.
    • Improved duration estimation by 3%p (14%p -> 11%p)
    • After building the model I specialized more in data pipeline, so I’m fluent with data science libraries that are used for data pipelines, such as Spark/Pandas/Polars/Numpy/Airflow.
    • By configuring our team’s spark sessions, our team’s Spark applications saw 10% speed improvements.
  3. Real-time Wifi Positioning System(2023-2024)
    • When trying to implement Public Transportation Navigation service, there was one problem: we can’t use GPS to locate users’ real-time location in subway stations
    • Used user’s WIFI logs and labeled field data to figure out Wifis that belong to each station.
    • DBSCAN to filter out train’s highly mobile Wifi, then use RSSI/GPS related features to
    • For 4000 labeled Wifi Station data on all Korean Subway, acheived accuracy and precision above 95% - signed off and made Naver’s Navigation Service Possible
    • In 2024,

2. Side Projects

  • FFXIV SimHelper, an In-Depth, Multi-Purpose DPS Simulation for FFXIV simhelper

  • FFXIV Speedkill Tracker, a speedkill tracking tool by phase
  • Wandervogels, an indie SRPG of three characters lost in this world.

contacts: