Jongyoul Lee
Senior Software Engineer at enechain Corporation
Tokyo, Japan
Summary
🤩
Rockstar🎓
Top SchoolJongyoul Lee is a senior software engineer based in Tokyo with 11 years of experience building large-scale distributed systems and data platforms. He has deep backend expertise in Apache Spark and Zeppelin, contributing notable fixes and Mesos/YARN integration improvements to the widely used Apache Spark project and adding YARN client support to Zeppelin. His career spans hands-on roles running 400+ node Spark clusters, operating Kafka at messaging scale, and designing enterprise notebook and data-pipeline services for companies like LINE and Agoda. As a long-time Apache committer and current PMC Chair, he blends open-source stewardship with delivery at product companies and startups. Notably, he pairs low-level systems work—executor launching, task-state handling, resource offer management—with pragmatic enterprise features like multi-tenancy and permissioned data portals.
11 years of coding experience
18 years of employment as a software developer
BS, Electrical Engineering, BS, Electrical Engineering at Seoul National University
English, Korean, Japanese
Stackoverflow
11reputation
529reached
1answer
0questions
Github Skills (18)
mesos10
apache-spark10
spark10
back-end-development10
big-data10
java10
scala10
javas10
yarn310
yarnpkg10
yarn-berry10
yarn210
build-configuration9
apache-zeppelin6
automations5
Programming languages (8)
Github contributions (5)
apache/zeppelin
Jun 2016 - Jan 2023
Web-based notebook that enables data-driven, interactive data analytics and collaborative documents with SQL, Scala and more.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:435 reviews, 86 commits, 553 PRs in 6 years 8 months
Contributions summary:Jongyoul primarily contributed to the implementation and enhancement of the Spark interpreter within the Apache Zeppelin project. Their work focused on adding support for yarn-client mode, which involved modifying the SparkInterpreter.java file, modifying and adding build configurations for YARN, adding configurations in zeppelin-env.sh and updating the README file. The user also updated the code related to configuration files. These changes indicate a focus on backend development and integration with distributed computing frameworks.
data-drivendata-analyticsanalyticsnosqlflink
apache/spark
Jan 2015 - May 2018
Apache Spark - A unified analytics engine for large-scale data processing
Role in this project:Back-end Developer
Back-end DeveloperContributions:16 PRs, 112 comments in 3 years 4 months
Contributions summary:Jongyoul primarily focused on enhancing the Apache Spark's Mesos integration. Their contributions include fixing bugs related to user permissions and task launching within the Mesos environment. They also improved the Mesos integration by declining unused resource offers, updating configurations, and resolving buffer issues related to task data serialization. Additionally, the user refactored code related to executor launching using spark-class, and improved the handling of task states within the Mesos scheduler.
analyticspythondata-processingsqlapache
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