Junyi Chai
Principal Applied Scientist at Microsoft
Pasadena, California, United States
Summary
👤
Senior🎓
Top SchoolJunyi Chai is a Principal Applied Scientist with 11 years of experience designing and shipping large-scale machine learning systems that serve millions of users. He led development of post-training LLM capabilities for Alexa Plus at Amazon, materially boosting agentic behavior for a high-profile product launch, and earlier improved auction efficiency for Sponsored Brands Ads through auto-tuning and reserve-price frameworks. At Microsoft he drove cross-market natural language generation that automatically created billions of ads, plus advances in query understanding, embedding-based click prediction, and knowledge mining. His background spans NLP, search and ads, recommendation systems, and quant finance, grounded in a Ph.D. from Princeton and hands-on GPU-accelerated quant work at Barclays. Known for translating deep research into production impact, he holds multiple patents and publications in top-tier venues. Based in Pasadena, he blends rigorous academic training with pragmatic engineering that scales.
11 years of coding experience
10 years of employment as a software developer
Master of Science - MS Computer Science, Master of Science - MS Computer Science at Georgia Institute of TechnologyBachelor of Science (BS) Physics, Bachelor of Science (BS) Physics at Peking UniversityDoctor of Philosophy (PhD) Atmospheric and Oceanic Sciences, Doctor of Philosophy (PhD) Atmospheric and Oceanic Sciences at Princeton University
Github Skills (3)
google-search3
apify2
serp-api1
Programming languages (2)
Github contributions (5)
mathsam/qg_model
Nov 2014 - Apr 2016
Contributions:35 commits, 19 pushes, 1 branch in 1 year 5 months
mathsam/fluid_dynamics_analysis
Dec 2014 - Apr 2016
Contributions:47 commits, 36 pushes in 1 year 4 months
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.