Qinfan Wu
Software Engineer at Facebook
Menlo Park, California, United States
Summary
🤩
Rockstar🎓
Top SchoolQinfan Wu is a software engineer with 11 years of experience building high-performance back-end systems at Facebook, based in Menlo Park. He specializes in low-level memory management and allocator performance, with notable open-source contributions to widely used projects like folly, fbthrift, and jemalloc. His work includes integrating jemalloc features (sdallocx), refactoring thrift internals to modern C++/Rust standards, and optimizing chunk maps and dirty-run handling to improve cache locality and reduce page faults. As an engineering intern he delivered measurable system gains—15–20% fewer page faults and a few percent fewer cache misses—results that scaled into production. Comfortable working across C++, Rust, and systems tooling, he blends deep systems knowledge with a pragmatic focus on measurable performance improvements. Collected training from Tsinghua and Columbia underpins his strong formal background in engineering and computer science.
11 years of coding experience
Master of Science (M.S.), Computer Science, Master of Science (M.S.), Computer Science at Columbia University in the City of New YorkBachelor of Engineering (B.E.), Automation Engineer Technology/Technician, Bachelor of Engineering (B.E.), Automation Engineer Technology/Technician at Tsinghua University
English, Chinese
Github Skills (17)
algorithm10
algorithms10
c-language10
memory-management10
c1110
data-structure10
refactor10
c1710
performance-optimization10
data-structures10
rust10
refactoring10
cprogramming-language10
thrift10
api-design9
Programming languages (6)
Github contributions (5)
facebook/fbthrift
Dec 2015 - Oct 2022
Facebook's branch of Apache Thrift, including a new C++ server.
Role in this project:
Backend Developer
Backend DeveloperContributions:21 commits in 6 years 11 months
Contributions summary:Qinfan primarily focused on refactoring and improving the codebase, specifically addressing deprecated code and improving the efficiency of the compiler. They removed deprecated classes and structures in C++, and added unit tests for decoding enums. Furthermore, the user made various improvements to the Rust code by fixing clippy warnings and refactoring. They also added functionality to support RPC options in the Thrift framework.
cppapache-thriftc-plus-plusapachefacebook
jemalloc/jemalloc
Jul 2014 - Jul 2017
Role in this project:Back-end Developer
Back-end DeveloperContributions:12 commits, 4 PRs, 1 issue in 3 years
Contributions summary:Qinfan primarily focused on debugging and improving the performance of memory allocation within the jemalloc library. Their contributions included fixing a bug related to memory allocation, reintroducing a crucial comment, and refactoring the chunk map to improve cache locality. They also made enhancements related to maintaining and managing dirty runs within the arena, improving the efficiency of memory management.
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