Timothy D. Sweetser
Machine Learning Engineer in New York City
Experience
Warner Brothers Discovery, New York, NY
Staff Machine Learning Engineer. October 2023 - Present
Senior Machine Learning Engineer. November 2020 - September 2023
- Reponsible for scaling and innovation of recommender systems and personalization for Max and HBO Max
- Scale personalization algorithms to tens of millions of users using Airflow, Docker, and Spark
- Increase user engagement of personalized recommendations tray using EASE model and XGBoost ensemble
- Move from offline to online scoring using custom Tensorflow Serving implementation
- Improve personalized recommendations using variational autoencoders (prototype)
FindMine, New York, NY
Machine Learning Engineer. May 2019 - November 2020
- Increase click through rate by 3% using \(\epsilon\)-greedy bandit
- Use deep learning to identify similar styles based on images
- Reduce costs by $50K/year by automatically replacing out of stock items in expert-curated fashion outfits
- Save $60K/year in cloud computing costs by shifting computation from database to Python layer
- Write a Flask app to collect quantitative fashion ratings from subject matter experts
Rent the Runway, New York, NY
Data Scientist, August 2018 - April 2019
- Develop fit algorithm to boost rental wear rate by +0.01
- Increase user engagement by improving personalized recommendations
- Rewrite production recommendation service using
asyncio, an asynchronous Python web framework
- Migrate batch model training from laptops to Jenkins
Stitch Fix, San Francisco, CA
Data Scientist. July 2015 - June 2018
- Develop personalized recommender systems for women’s clothing and implement them in production
- Increased revenue by $8+ million per year by quantifying style
- Use contextual bandits to optimize where and when to show different recommendations
- Develop end-to-end data science pipelines in Spark, Python and R using AWS, Docker, and Jenkins
Education
- M.S. Statistics, Stanford University, 2015
- B.A. Mathematics, Clark University, Worcester, MA
Programming Skills
- Advanced Python (numpy, scipy, pandas, scikit-learn, pytest, tensorflow, keras, Airflow, PySpark)
- Advanced SQL
- Basic scala and Golang
- Proficient with git, docker, AWS (Sagemaker, EMR), and bash