Dandan Zheng
Verified Expert in Engineering
Data Scientist and Developer
Katy, United States
Toptal member since June 2, 2022
Dandan is a senior data analyst and data scientist with 5+ years of professional experience and an extensive background in predictive models, AB testing, dashboard, and end-to-end analytics projects. She has worked in the technology, live streaming, social media platform, and oil and gas energy industries, constantly collaborating with cross-functional teams. Besides work, Dandan enjoys traveling and is a big-time computer gamer.
Portfolio
Experience
- Data Analysis - 5 years
- Dashboards - 5 years
- Data Science - 5 years
- SQL - 5 years
- Machine Learning - 5 years
- Python - 5 years
- Agile Project Management - 3 years
- A/B Testing - 2 years
Preferred Environment
Windows
The most amazing...
...project I've developed is Tiktok's live streaming user labels to analyze user experience, quality of streams, and potential areas of growth worldwide.
Work Experience
Data Analyst
ByteDance | TikTok
- Led and developed TikTok live streaming quality user profile system based on user experience and service of quality metrics. Classified and predicted user labels for customized strategies and applied them to billions of TikTok live users worldwide.
- Designed and created a dashboard of key metrics and trend analysis for business lines such as eCommerce and visual quality and conducted root cause analysis on key metrics changes weekly.
- Created and conducted AB tests on live streaming quality strategies, defined AB test design and analysis guidelines, and improved user experiences and engagement worldwide.
- Developed and maintained data pipelines for data security and data center migration and optimized data pipelines that process billions of data every day.
- Managed the live streaming quality data analysis team, mentored junior analysts, planned the team objectives, and generated reports for senior managers in and across departments.
Senior Analyst
Hess
- Designed and developed prediction models for equipment failure. Collaborated with teams from SMEs for feature extraction and business value and implemented models in Databricks, Dataiku, and Spotfire with scheduled updates.
- Analyzed treatment effectiveness using a time-varying survival model, clustering, and statistical tests. Calculated features, identified trends leading to cause, and communicated the financial evaluations and preventive maintenance recommendations.
- Created and instructed the "analytics academy" courses to promote a company-wide analytics culture, acting as a pivotal contributor in leading training and awareness efforts on analytics across the company.
- Developed daily metrics, trip simulations, and customized calculations for drilling economic analysis.
- Designed and developed a key dashboard that measures daily performance, cost and profit, incidents, and plans for drilling, which the department uses on a daily basis.
Experience
Segmented User to Customized Strategy
Realtime Time Series Equipment Failure Machine Learning Prediction Model
The development included:
1. Data gathering
2. Data cleaning
3. Feature development
4. Model creation, training, and optimization
5. Model implementation into production
6. Usage education and maintenance.
Education
Master's Degree in Engineering
University of Texas at Austin - Austin, Texas, USA
Certifications
Microsoft Certified: Azure Data Scientist Associate
Microsoft
AWS Certified Machine Learning – Specialty
AWS Amazon
Skills
Tools
Spotfire
Languages
SQL, Python
Paradigms
Agile Project Management
Platforms
Databricks, Dataiku
Storage
Data Pipelines
Other
Data Analysis, Machine Learning, Dashboards, Data Science, Modeling, A/B Testing, Predictive Modeling, Unsupervised Learning, Experimental Design
How to Work with Toptal
Toptal matches you directly with global industry experts from our network in hours—not weeks or months.
Share your needs
Choose your talent
Start your risk-free talent trial
Top talent is in high demand.
Start hiring