Summary
Overview
Work History
Education
Skills
Certifications Awards
Timeline
Generic
Lee Jaehyeok

Lee Jaehyeok

Machine Learning Engineer
Seoul

Summary

I constantly seek to understand what people like and why. With a data-driven approach to real-world problems, I strive to develop products and strategies that genuinely improve people’s lives. To achieve this, I study data science and artificial intelligence, applying them to solve meaningful challenges. I aim to become someone who can build the products I envision by gaining hands-on experience across various domains and strengthening my development skills.

Overview

1
1
year of professional experience
9
9
years of post-secondary education

Work History

ML Engineer Intern

Dnotitia
Seoul, Seoul
01.2025 - 03.2025
  • Developing and Training Embedding Models for Korean Retrieval Tasks
  • Contrastive Pre-Training with Token-Based Efficient Batching
  • Supervised Fine-Tuning with Hard Negative Mining

Data Operation Assistant

Mathpresso
Seoul, Seoul
09.2024 - 12.2024
  • Develop a chatbot (MVP) for the purpose of researching data while performing a student's assignment based on Web Data RAG (Role: structuring pipeline, overall prompt engineering and part of BE)
  • Build Vector DB migration pipeline through experiments. Improved Retrieval performance (NDCG score: 0.90 -> 0.95) through text data containment
  • Build a system for tuning prompts aimed at improving the performance of 'Problem-solving AI' (LLM-as-a-judge with Human Preference Criteria)

AI Engineer Internship

LG CNS
06.2024 - 08.2024
  • Building a RAG-based chatbot system based on company's own documents

Data Analyst Internship

LoadComplete
Pangyo
01.2024 - 02.2024
  • Model a new user churn prediction model and build a personalization push notification pipeline. Create more than 100 customer behavior expression features. (A/B test shows a 10% increase in D4 retention)

Education

Bachelor of Science - Industrial Engineering

Seoul National University
Seoul
03.2019 - 08.2025

High School Diploma -

Gwangju Science Academy
Gwangju
03.2016 - 02.2019

Skills

  • Communication

  • Leadership

  • Grit

  • Empathy

  • Self-Awareness

Certifications Awards

  • SQLD, 04/2024
  • 빅데이터 기반 금융 투자모형 연구 (2 등), 08/2023
  • TOEIC, 895, 03/2022

Timeline

ML Engineer Intern

Dnotitia
01.2025 - 03.2025

Data Operation Assistant

Mathpresso
09.2024 - 12.2024

AI Engineer Internship

LG CNS
06.2024 - 08.2024

Data Analyst Internship

LoadComplete
01.2024 - 02.2024

Bachelor of Science - Industrial Engineering

Seoul National University
03.2019 - 08.2025

High School Diploma -

Gwangju Science Academy
03.2016 - 02.2019
Lee JaehyeokMachine Learning Engineer