Kai Sun
Software Engineering Intern at Cockroach Labs
Waterloo, Ontario, Canada
Summary
🤩
Rockstar🎓
Top SchoolKai Sun is a software engineer focused on distributed systems, low-latency infrastructure, and algorithmic performance, currently interning on Cockroach Labs' backend and database team. A University of Waterloo CS student with a statistics minor, Kai has repeatedly shipped production-grade improvements at Snowflake, Google Cloud (GKE), Jane Street, SingleStore, and BlackBerry, often optimizing failure recovery, query planning, and observability. He contributed to CockroachDB by adding IO-overload metrics, improving MVCC command pagination, and enhancing load-splitter observability—work that speaks to deep database internals expertise. Kai also has research experience in cooperative self-driving communications at Uber ATG and a knack for simulating realistic failure modes (including crypto-exchange network simulators). A competitive mathematician with an IMO Silver medal and Putnam honors, he pairs rigorous problem-solving with pragmatic engineering to accelerate distributed systems resilience and efficiency.
8 years of coding experience
1 year of employment as a software developer
Bachelor's degree, Bachelor of Computer Science with Statistics Minor, 96%, Bachelor's degree, Bachelor of Computer Science with Statistics Minor, 96% at University of Waterloo
Github Skills (8)
databases10
go10
distributed-database10
performance-optimization10
database10
testing9
sql9
observability9
Programming languages (6)
Github contributions (5)
cockroachdb/cockroach
Sep 2022 - Jan 2023
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:35 reviews, 15 commits, 28 PRs in 4 months
Contributions summary:Kai contributed significantly to the CockroachDB database, focusing on improving the observability and performance of the system. They implemented a new metric `admission.io.overload` to track the store's IOThreshold and added observability for the load-based splitter to help with debugging. Furthermore, the user refactored and added pagination to multiple MVCC commands to enhance efficiency and handle large data volumes in intent resolution. These changes demonstrate a deep understanding of database internals and performance optimization.
distributed-sqldistributed-sql-databasemysqlsql-databasesql
KaiSun314/personal-website
Jan 2019 - Jan 2022
My personal website
Contributions:2 PRs, 52 pushes, 3 branches in 3 years
reactnextjs
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