Senior Software Engineer

About the role

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.