Senior Data Scientist

About the Role

At SumUp, we're on a mission to empower small businesses across the globe by providing a vast set of simple and affordable business tools to help them start, run, and grow their businesses. Lending at SumUp is a mature, scaled business with a strong and proven credit risk foundation. Our core models and decisioning frameworks are already robust and in production; as our portfolio grows, our challenge is safely extracting marginal gains from a complex system where changes are incremental and the stakes are high. As a Senior Data Scientist, you will be highly hands-on and embedded in day-to-day lending decisions. This role exists to strengthen our ability to improve what already works, reduce operational risk, and ensure long-term reliability as we scale into new markets. You will work within the Credit Risk Analytics (CRA) team, a streamlined group responsible for the modeling and analytics that underpin our global lending portfolio.

What you’ll do

Optimise Credit Risk Models: Iterate on existing models to improve stability, predictive power, and net revenue impact while performing deep dives to support risk decisions.

Drive End-to-End Deployment: Develop, test, and deploy new model versions in close collaboration with Credit Risk Engineering (CRE), ensuring no regressions or operational issues.

Enhance ML Infrastructure: Improve machine learning pipelines and workflows to reduce maintenance overhead and failure modes.

Integrate New Data: Evaluate and integrate new internal and external data sources (e.g., credit bureaus, open banking) into existing models and processes.

Monitor Performance: Closely monitor models in production, investigating performance shifts or anomalies to maintain portfolio integrity.

Promote Technical Excellence: Document work clearly and participate in code reviews, design discussions, and pair programming to maintain high-quality standards.

What makes you great for this position

5+ years of experience as a Data Scient