Senior Data Scientist

Founded in 2009, Zest AI is transforming the $17 trillion U.S. consumer credit market through AI-driven technology that helps lenders identify creditworthy borrowers overlooked by traditional methods. Our platform enables financial institutions of all sizes to harness AI to improve underwriting accuracy, expand credit access, and deliver better lending experiences.

With more than 600 active AI models and over 50 issued and pending patents, Zest AI provides solutions across marketing, underwriting, fraud detection, and lending intelligence. Headquartered in Los Angeles, Zest AI partners with financial institutions to make smarter lending decisions while strengthening the resilience of the U.S. financial system.

Data Scientists at Zest AI use the power of machine learning (ML) and statistical analysis to build, test, deploy, and monitor financial underwriting models. These models are providing fairer and transparent access to credit and have already had a substantial impact - scoring millions of Americans on over $180B in assets. By leveraging a combination of ML and vast amounts of data points, Zest seeks to challenge traditional credit scoring models, while expanding our proprietary AI-explainability technology across the fintech industry.

Why this role is exciting

• Work on high-impact ML systems powering real credit decisions across $180B+ in assets
• Build and deploy production machine learning models used by financial institutions nationwide
• Solve complex modeling challenges involving large-scale tabular data, explainability, and regulatory constraints
• Collaborate with ML engineers, product leaders, and domain experts to bring models from research → production → measurable business outcomes

In this role you will

• Translate unstructured business problems into well-defined machine learning projects
• Collaborate with Engineers, Product Managers, and Data Analysts to identify high-impact opportunities for modeling
• Design, train, and deploy production machine learning models used in real-world credit underwriting decisions
• Develop highly generalizable models for predicting a range of financial outcomes
• Incorporate modeling insights back into product development to drive continuous improvement
• Build prototypes, experiments, and modeling frameworks to validate new approaches
• Create demos, documentation, and internal resources to help teams effectively leverage modeling work
• Take ownership of modeling implementation in real-world environments to deliver measurable customer value

We are looking for:

• MS or PhD in a quantitative field such as Computer Science, Engineering, Physics, Mathematics, or a related discipline (financial services experience is a plus)
• Strong foundation in programming, statistics, mathematics, and classical machine learning techniques, including tree-based methods, optimization, supervised and unsupervised learning, and feature engineering
• Experience designing, developing, and deploying machine learning models in production environments
• Hands-on experience with machine learning frameworks such as XGBoost, Scikit-learn, or similar libraries
• Solid understanding of system-level considerations for ML development, including memory usage, disk I/O, and CPU/GPU utilization
• Experience with modern software engineering practices, including modular code design, version control, and maintainable codebases
• Strong proficiency in Python
• Passion for applying machine learning and AI to solve real-world problems and drive meaningful impact

Perks and benefits:

All Zestys experience:

• The opportunity to join a mission-focused company
• People – the best part of Zest
• Robust medical, dental and vision insurance plans
• Annual bonus plan participation
• 401(k) with generous match
• Employee Awards and Recognition
• 11 company holidays
• Winter break (office closed between Christmas and New Year's Day)
• Unlimited vacation time
• Employee Resource Groups
• Generous family leave policy (12 week maternity leave / 6 week paternity leave)
• Phone, internet, wellness, and professional development allowances
• Employee gatherings, including Town Hall meetings

Additionally, our Burbank, CA hybrid Zestys enjoy:

• Beautiful, modern, dog-friendly office with lounge areas, video games, and gigantic jigsaw puzzles
• Daily catered lunches from LA’s best restaurants and a fully stocked kitchen
• Complimentary manicures, pedicures, and mindfulness sessions
• Company happy hours, social events, outings, and much more!

About Zest AI:

Creating a diverse and inclusive culture where all are welcomed, valued, and empowered to achieve our full potential is important to who we are and where we’re headed in the future. We know that unique backgrounds, experiences, and perspectives help us think bigger, spark innovation, and succeed together. Zest is committed to diversity, equity, and inclusion and encourages professionals from underrepresented groups in technology and financial services to apply.

Our core values are Communication, Collaboration, Bias for Action, Client-centricity, and Heart. Learn , follow us on LinkedIn (linkedin.com/company/zest-ai/) or Twitter @Zest_AI, or check out our Insights blog (