Xiaochen Cui
Software Engineer at Varonis
Vancouver, British Columbia, Canada
Summary
👤
Senior🎓
Top SchoolXiaochen Cui is a software engineer with 11 years’ experience specializing in database kernels, system programming, and high-performance back-end engineering. He has driven substantial performance wins—designing a vectorized query engine that made an analytical DB 50–300x faster, reworking storage formats to cut disk footprint by 70% and boost IO nearly 3x, and building an IoT gateway that handled up to one million packets per second. A contributor to the flagship CockroachDB project, he has shipped core SQL and time-handling fixes that improve Postgres compatibility and consistency in a widely used distributed SQL database. Comfortable across Go, low-level optimization (SIMD), and cloud-native tooling, he also shortens release cycles and automates operations in production environments. Based in Vancouver with fluent English and a take-it-easy Github ethos, he blends deep systems expertise with pragmatic engineering that reduces complexity and bugs.
11 years of coding experience
6 years of employment as a software developer
Bachelor's degree, Computer Software Engineering, Bachelor's degree, Computer Software Engineering at Tianjin Polytechnic UniversityMaster of Science - MS, Applied Computer Science, Master of Science - MS, Applied Computer Science at Fairleigh Dickinson University
English, Chinese
Github Skills (15)
databases10
query-optimization10
sql-query10
timestamps10
unix-timestamp10
go10
timestamp10
distributed-database10
cockroachdb10
optimisation10
sql10
database10
optimization10
data-structure7
data-structures7
Programming languages (18)
Github contributions (5)
cockroachdb/cockroach
Jul 2021 - Feb 2025
CockroachDB — the cloud native, distributed SQL database designed for high availability, effortless scale, and control over data placement.
Role in this project:
Back-end Developer / Database Engineer
Back-end Developer / Database EngineerContributions:26 reviews, 12 PRs, 80 comments in 3 years 8 months
Contributions summary:Xiaochen primarily contributed to the database's core functionality, focusing on SQL query optimization and consistency with Postgres. They implemented sorting logic for overload functions and addressed inconsistencies related to timestamp handling, specifically concerning 'infinity' values. Additionally, the user made changes to the changefeed jobs and database quantile calculations. Their work included modifications across multiple files related to SQL, stats, and timeutil packages, indicating a deep understanding of the CockroachDB codebase and its internal workings.
distributed-sqldistributed-sql-databasemysqlsql-databasesql
XiaochenCui/XiaochenCui.github.io
Sep 2017 - Dec 2022
Contributions:371 commits, 577 pushes, 3 branches in 5 years 3 months
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