Jiajun Sun
Software Engineer at ByteDance
Mountain View, California, United States
Summary
🤩
Rockstar🎓
Top SchoolJiajun Sun is a software engineer in Mountain View with seven years of experience building ML and AI systems, currently working on applied machine learning at ByteDance after contributing to AWS SageMaker. He blends a strong research background (Stanford MS, 3.9) and applied computer vision/data science experience from Blue River and earlier research roles with production engineering skills demonstrated at AWS. An Apache Calcite committer, he has deep back-end SQL expertise—implementing functions like APPROX_COUNT_DISTINCT, CHAR, and dynamic LIMIT/OFFSET handling—and has improved dialect compatibility across major engines. Comfortable moving between low-level data systems and higher-level ML services, he focuses on LLM/AGI work while maintaining a pragmatic track record of shipping robust, standards-aware code.
7 years of coding experience
6 years of employment as a software developer
Master of Science - MS, 3.9, Master of Science - MS, 3.9 at Stanford UniversityBachelor’s Degree, Civil Engineering, Bachelor’s Degree, Civil Engineering at Tongji UniversityBachelor’s Degree, Civil Engineering, First Class Honour, Bachelor’s Degree, Civil Engineering, First Class Honour at Monash University
English, Chinese
Github Skills (5)
apache-calcite10
javas10
sql10
java10
big-data8
Programming languages (4)
Github contributions (5)
apache/calcite
Nov 2021 - Nov 2022
Apache Calcite
Role in this project:
Back-end Developer
Back-end DeveloperContributions:370 reviews, 21 commits, 112 PRs in 1 year
Contributions summary:Jiajun primarily contributed to the core logic of the Apache Calcite project, focusing on enhancing the SQL dialect support. Their work involved implementing the `APPROX_COUNT_DISTINCT` function for various SQL dialects and fixing issues related to view expansion. Furthermore, the user added support for handling dynamic parameters in `LIMIT` and `OFFSET` clauses and corrected the handling of parentheses in `UNION` queries. They also made updates related to the serialization and deserialization of the `Snapshot` operator, and added the implementation for the `CHAR` function for MySQL and Spark SQL dialects.
geospatialapache-calcitesqlapachebig-data
JiajunBernoulli/calcite
Jun 2021 - Oct 2024
Contributions:2 reviews, 35 PRs, 204 pushes in 3 years 4 months
accumuloapache-calciteapachebig-datadatastream
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