Chao Sun
Member Of Technical Staff at The Apache Software Foundation
Sunnyvale, California, United States
Summary
🤩
Rockstar🎓
Top SchoolChao Sun is a seasoned backend engineer with 14 years of experience designing and optimizing distributed data systems, currently a Member of Technical Staff at OpenAI and an active committer and PMC member across multiple Apache projects. He has led and shipped large-scale storage and query engine features—ObserverNameNode, storage-partitioned joins, and Parquet/vectorized reader improvements—that materially improved performance and scalability at companies like Uber and Apple. A core contributor to Apache Hadoop, Spark, Arrow, DataFusion and Hive, he bridges Rust and JVM ecosystems, implementing low-level buffer/array optimizations and SQL optimizer rules alike. He headed a team building DataFusion Comet, a native vectorized execution engine for Spark, demonstrating both technical leadership and systems-level innovation. Based in Sunnyvale, he combines PhD-level rigor with pragmatic production experience and a knack for squeezing performance from complex data paths. Notably, his work on read-from-standby/observer NameNodes and bit-packed boolean vectors shows attention to both high-throughput RPC scaling and memory-level efficiency.
14 years of coding experience
10 years of employment as a software developer
Doctor of Philosophy (Ph.D.) Computer Science, Doctor of Philosophy (Ph.D.) Computer Science at University of Wisconsin-MilwaukeeMaster's degree Computer Science, Master's degree Computer Science at Nanjing University
English, Chinese
Github Skills (38)
code-optimization10
spark10
buffer10
buffering10
set-operations10
bit-manipulation10
operation10
high-availability10
dataframes10
memory-management10
big-data10
hdfs10
array-merge10
data-structure10
java10
Programming languages (11)
Github contributions (5)
apache/hadoop
Feb 2018 - Mar 2022
Apache Hadoop
Role in this project:
Back-end Developer
Back-end DeveloperContributions:133 reviews, 110 commits, 53 PRs in 4 years
Contributions summary:Chao Sun contributed to various aspects of the Hadoop project, focusing on enhancing the HDFS (Hadoop Distributed File System) functionality. His work included fixing a crash in the Quorum Journal Manager (QJM), adding checks for write operations, refactoring the ConfiguredFailoverProxyProvider, and implementing changes to support reads from standby NameNodes and Observer nodes. Sun's contributions also encompassed addressing BlockMissingException when reading from an observer. These modifications improved the reliability, stability, and functionality of the Hadoop ecosystem.
apachebig-datasparkhadoopjava
apache/hive
Feb 2015 - Aug 2021
Apache Hive
Role in this project:Back-end Developer
Back-end DeveloperContributions:100 reviews, 131 commits, 107 PRs in 6 years 6 months
Contributions summary:Chao primarily contributed to the Apache Hive project, focusing on resolving issues related to dynamic partition table insertion errors, and implementing settings for Spark, specifically related to Kryo settings, RSC failures, and MapJoin replications. They also addressed a problem in the HBase integration and improved the time format used in query plan generation. Their work is heavily involved in Spark integration and optimization within the Apache Hive ecosystem.
flinksqlapachebig-dataspark
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