# Xiyuan Liu > Staff Software Engineer @ Lumos Location: San Francisco Bay Area, United States Profile: https://flows.cv/xiyuan Experienced Senior Staff Software Engineer and Tech Lead with a strong leadership, development, and architecture background. Proven track record of building and scaling high-performing teams and establishing robust engineering culture. Strong hands-on coding skills and technical leadership abilities in designing and developing features focusing on performance and quality. ## Work Experience ### Staff Software Engineer @ Lumos Jan 2023 – Present | San Francisco Bay Area ### Senior Staff Software Engineer @ Firework Jan 2023 – Jan 2023 | San Mateo, California, United States - Leadership & Team Growth: Expanded the Web team from 7 to 15 engineers, fostered a testing culture, increasing test coverage from 0 to 90%, and established code review processes, increasing team reviews to 50 PRs/month. - Process & Tooling: Spearheaded company-wide Jira setup, established scrum processes across teams, and introduced tools like Cypress Cloud and Sentry, reducing runtime errors by 50%. - Technical Innovation: Built an RTC-based infrastructure reducing live stream latency from 5s to 300ms, and drove web performance improvements such as reducing CPU usage during live streams by 80%. - Product Enhancement & Support: Revamped product scripts, reduced tech support requests by 80%, and directly supported the sales team in securing multi-million dollar deals. ### Staff Software Engineer @ Firework Jan 2022 – Jan 2023 | San Mateo, California, United States ### Staff Software Engineer @ YouTube Jan 2021 – Jan 2022 ### Senior Software Engineer @ YouTube Jan 2018 – Jan 2021 - Designed and developed core JavaScript libraries that power over 20+ YouTube web applications, including those used on desktop, mobile, and living room devices. - Led the development of web storage libraries within YouTube and served as the point of contact for all web storage-related issues. Enabled YouTube web applications to persist large amounts of data reliably. - Evaluated various web frameworks, including React, Angular, and Google's internal frameworks, and influenced the selection of the next-generation framework for YouTube web applications. Additionally, developed an internal web framework for Living Room web applications. - Streamlined state management solutions across YouTube applications by integrating Redux. Simplified the sharing of features across applications. ### Software Engineer @ YouTube Jan 2015 – Jan 2018 | San Bruno, California, United States Tech lead of development team for YouTube on TV. YouTube on TV delivers 10% of all YouTube traffic, about 100 million hours of watch time per day. The application is available on TV sets and gaming consoles. It shots up 70 percent every year and has been one of the fastest growing YouTube platforms. ### Software Engineer @ GREE, Inc. Jan 2013 – Jan 2015 | San Francisco Bay Area ## Education ### Master of Entertainment Technology in Entertainment Technology Carnegie Mellon University Jan 2011 – Jan 2013 ### Software engineering/Diplôme d'ingenieur informatique in Computer science/Informatique INSA Toulouse - Institut National des Sciences Appliquées de Toulouse Jan 2006 – Jan 2011 ## Contact & Social - LinkedIn: https://linkedin.com/in/zeroliu --- Source: https://flows.cv/xiyuan JSON Resume: https://flows.cv/xiyuan/resume.json Last updated: 2026-03-22