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 Scientist (or 7+ years in data-related/software engineering fields with at least 3 years in Data Science).
• Deep understanding of Data Science principles, including statistics, probability theory, and machine learning concepts.
• Strong experience with Python (pandas, PySpark, scikit-learn) and SQL for complex data retrieval and manipulation
• Proven track record of building, evaluating, and deploying machine learning models end-to-end at scale.
• Experience with credit risk assessment, lending, or financial decisioning models.
• Strong software engineering practices, including writing clean, maintainable, testable code with version control and documentation.
• Collaborative and respectful team player who is comfortable voicing disagreements while committing to team decisions ("disagree and commit").
• Fluency in English with the ability to communicate technical findings clearly to diverse stakeholders.

 

Why you should join SumUp

🌎 Opportunity to work with SumUppers globally on large-scale fintech products used by millions of businesses worldwide, from our Barcelona office.

🌈 Commitment to Diversity and Inclusion: be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced.

🚀 Enrolment onto our Virtual Stock Option programme: you will own a stake in SumUp’s future success.

📚 A dedicated annual L&D budget of €2000 for your individual development, which you can be used to attend conferences and/or advancing your career through further education.

💶 A corporate pension scheme where we match up to 20% of your contributions.

🏖️ Generous time off: enjoy 28 days of paid leave plus public holidays and special leave days.

🚵🏾‍♂️ Numerous other benefits such as Urban Sports Club subsidy, Kita placement assistance, subsidised office lunches.

🌴 Break4me: 1-month sabbatical after 3 years of service.

🔗 Referral Bonus: earn additional rewards by referring talented individuals to join the SumUp team.

 

About SumUp

Be empowered to do more that matters. 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. Today, over 4 million businesses in 36 markets rely on SumUp as their financial partner to manage payments, finance and customer relationships.

 

Our commitment to small businesses is reflected in our diverse team of over 3,000 SumUppers from over 90 nationalities, united by global collaboration and an innovative mindset. Our core values lay the foundation for who we are and what we stand for, shaping our work culture and driving our success. We foster an inclusivity and continuous learning culture, providing a safe space for personal and professional growth. Our differences make us unique and strong as we strive to create an environment where everyone belongs and feels supported, no matter how they identify.

 

SumUp is proud to be an Equal Employment Opportunity employer, actively seeking and embracing diversity in our workforce. We don't make hiring or employment decisions based on race, colour, religion or religious belief, ethnic or national origin, nationality, sex, gender, gender identity, sexual orientation, disability, age or any other basis protected by applicable laws or prohibited by company policy. Our commitment extends beyond recruitment to creating a safe and respectful workplace where harassment of any form is strictly prohibited.