Janghyun Kim
Founder & Lead Engineer at Grooboost
Seoul, South Korea
Summary
🤩
Rockstar🎓
Top SchoolJanghyun Kim is a founder and lead engineer with a decade of hands-on experience architecting data-intensive backend systems, real-time game servers, and consumer mobile products. Based in Seoul, he has led end-to-end development and operation of services on GCP and AWS—ranging from a meal-planning app with cost and ingredient optimization to a custom tick-based MMORPG with cell-based AOI for scalable state sync. His background spans high-throughput telemetry and feature pipelines at Kakao Mobility, incentive systems at Amazon, and petabyte-scale ETL and ML-driven data quality platforms at Netmarble, bringing both production rigor and ML ops automation to product teams. Known for pragmatic system design, he blends deep distributed-systems thinking with product-focused UX flows to drive retention and operational simplicity. A subtle trademark is his playful Github bio class Life(var bitter: Int, var sweet: Int), hinting at a developer who balances engineering seriousness with human curiosity.
8 years of coding experience
10 years of employment as a software developer
Bachelor's degree Computer Science / Integrated Design, Bachelor's degree Computer Science / Integrated Design at Yonsei University
Korean, English
Github Skills (12)
atdd10
jpa10
java10
react9
typescript9
python8
spring-boot7
mvc6
aop6
mysql5
jdbc5
react-query2
Programming languages (5)
Github contributions (5)
zunior-team/java-racingcar-old
Jan 2020 - May 2020
자동차 경주용 게임을 관리하는 저장소
Contributions:22 PRs, 13 pushes, 8 branches in 4 months
javajpa
nokchax/algorithm
May 2019 - Aug 2021
Contributions:222 pushes, 1 branch in 2 years 3 months
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