# William Weiliang Li

> Machine Learning at Meta

Location: San Francisco Bay Area, United States
Profile: https://flows.cv/williamweiliangli

I am a machine learning scientist / software engineer / tech lead with solid math background and hands-on programming skills. I have rich experience in Ads industry (10+ yrs) with deep knowledge in Ads ranking & delivery systems and strong tech lead skills. I built up an ML engineering team from scratch, and the projects I led have delivered >$1 billion incremental revenue at Meta. My general interests are applying mathematical and statistical theories to solve challenging data-driven problems and deliver large impact to benefit our society.

Qualifications:
• 15-year R&D experience with expertise in machine learning, statistical analysis and optimization. Areas include classification & regression & clustering, time-series prediction, location estimation & tracking, and resource allocation.
• 10-year experience in Ad-tech industry with focus on designing Ad targeting/ranking models to drive clicks/conversions/click-conversions; Familiar with real-time bidding system, distributed model training & deployment pipelines, and A/B test experiments.
• Experience of production-scale software development with deep understanding of code reusability and readability. Projects involves ML pipeline architecting, object-oriented design and implementation, code refactoring, unit/integration testing, deployment and operational maintenance.
• Extensive experience with big data (petabyte-scale) techniques on distributed computing systems, such as Spark, MapReduce, Hadoop. 
• Proficiency in Java, Python, SQL, Shell and Jupyter notebook with various machine learning and statistical analysis tools (e.g., Sckit-Learn, NumPy, Tensorflow, Keras, XGBoost)
• Excellent communication and tech lead skills (experience of building an ML engineering team with 10+ engineers at Meta)

## Work Experience
### Staff Machine Learning Software Engineer @ Meta
Jan 2020 – Present | Menlo Park, California, United States
• Tech lead (Founder) of App Ads CoreML engineering team (50+) at Meta Monetization org
• Driving state-of-the-art ranking model development and new ML foundation innovations on Ads products that generated >$1 billion incremental revenue

### Sr. Modeling Scientist @ Quantcast
Jan 2015 – Jan 2020 | San Francisco Bay Area
• Designed and implemented various machine learning models for ads targeting, e.g., predicting clicks/conversions/clicks conversions, preventing fraudulent clicks, and forecasting RTB spend
• Developed a privacy-centric abstract representation model to improve conversion performance under EU general data protection regulation (GDPR)
• Developed our new model training platform 'QCLearn' (data preparation in MapReduce + AWS model trainer in Python) and refactored all production models to run on QCLearn
• Redesign and developed our new model training pipeline all in Spark
• Mentored engineers, scientist and interns on various modeling and platform development projects

### Postdoctoral Researcher @ UC Santa Barbara
Jan 2012 – Jan 2014 | Santa Barbara, California Area
• Designed statistical inference algorithms for indoor navigation using WiFi and inertial sensors
• Designed robust optimization techniques to maximize the energy efficiency of location-aware networks

### Postgraduate Researcher @ Massachusetts Institute of Technology
Jan 2009 – Jan 2011
• Developed algorithms to optimize data throughput of broadband and multi-antenna systems
• Designed regression models to characterize bandwidth scaling behavior in wireless systems


## Education
### Doctor of Philosophy (Ph.D.) in Information Engineering
The Chinese University of Hong Kong

### Visiting Ph.D. Student
Massachusetts Institute of Technology

### Master of Science (M.S.) in Electrical Engineering
Peking University

### Bachelor of Engineering (BEng) in Automation
Shanghai Jiao Tong University


## Contact & Social
- LinkedIn: https://linkedin.com/in/williamweiliangli

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Source: https://flows.cv/williamweiliangli
JSON Resume: https://flows.cv/williamweiliangli/resume.json
Last updated: 2026-04-12