Weijie Sun
Software Developer at Alibaba.com
Hangzhou City, Zhejiang, China
Summary
🤩
Rockstar🎓
Top SchoolWeijie Sun is a software developer with 11 years of experience, currently building the C++ SDK layer for an eBook reader at Alibaba.com in Hangzhou. He has deep grounding in algorithms, data structures, and operating systems—his favorite subject—and applies that knowledge to performance-sensitive backend work. As an open-source contributor, he implemented a 64-bit roaring bitmap variant and improved core logic, bug fixes, and performance of the widely used RoaringBitmap library (adopted by projects like Apache Spark and Netflix Atlas). Comfortable working at the intersection of low-level systems and application code, he focuses on correctness and efficiency in complex data structures. Trained at Tongji and Zhejiang universities, he combines solid academic foundations with a decade of production engineering.
11 years of coding experience
Bachelor's degree, Computer Science, Bachelor's degree, Computer Science at Tongji UniversityZhejiang University
Github Skills (9)
algorithm10
data-structures10
javas10
algorithms10
data-structure10
java10
bitset10
testing9
performance-optimization9
Programming languages (7)
Github contributions (5)
RoaringBitmap/RoaringBitmap
Jul 2020 - Nov 2021
A better compressed bitset in Java: used by Apache Spark, Netflix Atlas, Apache Pinot, Tablesaw, and many others
Role in this project:
Back-end Developer
Back-end DeveloperContributions:38 reviews, 5 commits, 21 PRs in 1 year 4 months
Contributions summary:Weijie primarily contributed to the core logic of the `roaringbitmap` library. Their work involved implementing a novel 64-bit roaring bitmap implementation, addressing issues related to data structures and algorithms. They also focused on bug fixes and performance improvements, particularly around the `and` operation and dealing with empty containers within the bitmap operations, and fixed a mismatch issue in the shim. The user made changes to testing files and core classes.
apache-pinotapache-sparkbitsetjavaroaring-bitmaps
weijietong/gporca
Jan 2018 - Feb 2023
Contributions:1 push in 5 years 1 month
queryquery-optimizersqlbig-datadatabase
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