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:
- 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:
- I was the first to add Team Coding Convention for the backend engine
- I doubled our backend server’s number of tests
- Provided documentation for the backend server’s hard-to-understand legacy parts as I refactored it.
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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.
- 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
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FFXIV SimHelper, an In-Depth, Multi-Purpose DPS Simulation for FFXIV
- FFXIV Speedkill Tracker, a speedkill tracking tool by phase
- Wandervogels, an indie SRPG of three characters lost in this world.
contacts:
- Github Account
- Email: junyeopna4@gmail.com
- Discord: Fly’xiv#5525