Rei Shimizu
Senior Software Engineer at LINE
Yokohama, Japan
Summary
👤
Senior🎓
Top SchoolRei Shimizu is a Senior Software Engineer based in Yokohama with eight years of experience building high-performance, scalable networking and cloud-native infrastructure. He designs and ships L7 proxies, load balancers, and service mesh platforms at scale—leading company-wide initiatives that run across hundreds of thousands of VMs and containerized microservices. Proficient in C++, Go, and Rust, Rei has a track record of heavy performance optimization (including a Rust rewrite that improved CPU efficiency 20x) and of producing lower-latency, cost-efficient alternatives to mainstream proxies. An active open-source maintainer and contributor, he’s shaped Envoy, Istio, and Apache SkyWalking integrations and speaks regularly at global conferences like KubeCon and ApacheCon. Beyond systems engineering, he contributes to language and localization efforts—maintaining the Japanese Swift project and co-authoring several translation books—bringing a rare mix of deep systems expertise and community stewardship.
8 years of coding experience
6 years of employment as a software developer
Master's degree, Computer Engineering, Master's degree, Computer Engineering at Waseda University
Japanese, Chinese
Github Skills (35)
programming-language10
visible10
swift10
api9
swift-framework8
swiftui8
swiftpm8
swiftlint8
async7
injection7
ios7
dependency-injection7
compiler7
compliance7
documentation6
Programming languages (6)
Github contributions (5)
stzn/swift-migration-guide-jp
May 2024 - Mar 2025
Japanese translation of https://github.com/apple/swift-migration-guide
Contributions:110 reviews, 65 PRs, 110 pushes in 10 months
swiftswift6
stzn/SwiftPodcast
Jan 2022 - Jan 2023
Documents for SwiftPodcast
Contributions:2 reviews, 196 commits, 2 PRs in 1 year 1 month
swiftswiftlint
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