Senior Software Engineer

At SumUp , we believe small merchants are the heartbeat of our communities. By joining the Lending team , you'll help keep a core credit product running for businesses across Europe and Brazil, one that's already proven, already trusted, and still has plenty of room to get better. As a Senior Backend Engineer , you'll be a technical anchor on the Servicing squad, operating with real autonomy to challenge existing patterns rather than just maintain them. This is a role for someone who's energised by complex, live systems, comfortable owning hard trade offs between speed and stability, and excited to help scale a regulated, high stakes platform without breaking what already works. What you'll do • Build and maintain backend services that power SumUp's lending platform in Go • Strengthen observability and monitoring so the team can measure system health and catch issues before they become incidents • Write integration tests that protect the reliability of every release • Help adapt the platform to new regulatory requirements as SumUp expands into new markets • Contribute to exploring and implementing new loan repayment flows • Investigate production incidents and balance fast fixes with long term platform stability You'll be great for this role if • Strong knowledge of backend development, with a clear focus on code quality and performance. • Experience questioning how an existing system works and proposing concrete, practical improvements. • Comfort working with observability and monitoring tools to understand system behaviour and define meaningful metrics. • Track record of using integration tests to validate the reliability of a service. • Ability to weigh deadlines against quality when building or evolving a production system, and to explain that trade off clearly. Why you should join SumUp 🌎 Opportunity to work with a truly global, multicultural team from our dynamic São Paulo hub in the heart of the city. This involves an office-first setup 🌈 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 R$ 10,000 for education, certifications, and conferences 🏖 Generous time off: enjoy 22 working days of paid leave, plus public holidays and special leave days 💪 Stay fit: Wellhub membership included and gym at the office 💼 Financial wellness: SumUp contributes to your private retirement plan with Santander 🧠 Mental well-being: access to Zenklub for therapy, coaching, and emotional wellness resources 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 simple and affordable tools that allow them to thrive. Today, over 4 million businesses in 39 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 4,000 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 inclusivity and a 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 employmen