Responsibilities
- Develop new functionality and maintain existing services across the codebase, primarily using Go.
- Advance the merchant risk decision framework beyond its MVP for fraud prevention, risk, and compliance use cases.
- Design, build, and maintain reliable distributed systems and backend services.
- Collaborate with product managers, data scientists, machine learning engineers, fraud strategy teams, and operational stakeholders.
- Shape technical direction, service boundaries, and system design decisions.
- Contribute to Python projects, including AI-agent initiatives.
- Participate in code reviews, testing, monitoring, and continuous improvement of production services.
- Use AI-assisted development tools while maintaining code quality, security, and maintainability.
- Be open to participating in an on-call rotation as production responsibilities evolve.
Requirements
- Professional experience developing software with Go/Golang.
- Experience building and operating distributed systems and backend services.
- Strong system design skills and understanding of reliable, maintainable software architecture.
- Experience with Kubernetes and Kafka.
- Working knowledge of Python and interest in Python-based products or AI-agentic development.
- Experience using AI-assisted tools in software development.
- Experience working in agile, cross-functional teams and with non-engineering stakeholders.
- A pragmatic, outcome-focused approach to defining MVPs, making trade-offs, and iteratively improving solutions.
- Collaborative communication skills and willingness to challenge ideas constructively.
- Motivation to learn about fintech, fraud prevention, risk, and compliance.
Benefits
- Office-first work setup from SumUp’s Sofia office.
- €2,000 annual learning and development budget for conferences or further education.
- Enrollment in the VSOP program with an ownership stake in SumUp’s future success.
- 25 days of paid leave, increasing by one day per year of service up to 35 days, plus public and special leave.
- 30-day sabbatical after completing three years of employment.
- Tax-free food vouchers and flexibility through the Re:Benefits platform.
- Free shuttle buses to Joliot-Curie metro station.
- Additional health and life insurance.
- On-site yoga and a co-sponsored Multisport card.
- Hack Days every second Friday and global Hack Weeks.
- Referral bonus program.
Tech Stack
Categories
About SumUp
SumUp is a leading global fintech company committed to levelling the playing field for small businesses. Founded in 2012, we’re the trusted partner of over 4 million merchants in 37 markets, providing simple and affordable tools that help them manage payments, finance, and customer relationships. Our vision is a world where everyone can build a thriving business. Guided by this, we champion small business ownership by creating accessible solutions that empower entrepreneurs to grow and succeed. Our diverse team of over 3,000 SumUppers — representing more than 90 nationalities across 20 offices worldwide — is at the heart of our success. Beyond business, we donate 1% of the net revenue generated by Solo devices to environmental causes and support educational and entrepreneurial initiatives around the world. Recognised as a Top Global Employer for inclusion by the Stonewall Workplace Equality Index in 2022 and 2023, and awarded Fintech Diversity Initiative of the Year at the Irish National Fintech Awards in 2025, SumUp continues to build an inclusive, supportive, and purpose-driven workplace where everyone belongs.