Zac Yu
Staff Software Engineer at Duolingo
Pittsburgh, Pennsylvania, United States
Summary
🤩
Rockstar🎓
Top SchoolZac Yu is a Staff Software Engineer with 12 years of experience building scalable web and system software, currently leading engineering efforts at Duolingo after a multi-year tenure at Google spanning SRE and product engineering roles. He blends a strong academic background in computer science and mathematics (MS, UT Austin; BPhil, Pitt) with hands-on full‑stack craft—evidenced by contributions to an open-source Bilibili browser extension where he improved video playback, subtitle downloads, and UI/UX. Comfortable across C++, JavaScript/Angular, Node.js and large distributed systems (Borg, Spanner, Protobuf), Zac has repeatedly shipped high‑impact production code and tooling to reduce operational noise and automate investigations. He pairs systems-level rigor from SRE work with front-end sensibility from web player and extension projects, making him effective at bridging backend reliability and user-facing features. Known for taking on new disciplines quickly, he mixes research experience in learning technologies and AR with practical product delivery.
12 years of coding experience
8 years of employment as a software developer
Junior High School, Junior High School at The Experimental High School Attached to Beijing Normal UniversityHigh School, High School at San Joaquin Memorial High SchoolBachelor of Philosophy Mathematics and Computer Science, Bachelor of Philosophy Mathematics and Computer Science at University of PittsburghMaster of Science - MS Computer Science, Master of Science - MS Computer Science at The University of Texas at AustinSummer Session Computer Science, Summer Session Computer Science at Stanford University
English, French, Japanese
Stackoverflow
25reputation
2kreached
0answers
2questions
Github Skills (16)
html10
css10
javascript10
web-development10
chrome-extension10
chrome-plugin10
chrome-app10
browser-extension10
kotlin6
location6
android6
firebase-realtime-database6
android-fragments6
firebase6
java6
Programming languages (8)
Github contributions (5)
bilibili-helper/bilibili-helper-o
Sep 2014 - Nov 2019
哔哩哔哩 (bilibili.com) 辅助工具，可以替换播放器、推送通知并进行一些快捷操作
Role in this project:
Full-stack Developer
Full-stack DeveloperContributions:18 releases, 253 commits, 21 PRs in 5 years 2 months
Contributions summary:Zac primarily worked on the front-end of the Bilibili Helper extension, focusing on improving the user interface and adding new features. Contributions include implementing ASS subtitle downloads, updating the HTML5 player, and modifying the download and playback functionality. They also made various style updates to improve the user experience on both the main video page and the generated video pages.
videobilibili
zacyu/js-boggle
Jul 2013 - Aug 2017
Contributions:13 commits, 2 PRs, 5 pushes in 4 years 1 month
gamecssjavascriptcss3html5
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.