Senior Go Backend Engineer – Fraud Risk & AI Systems

SumUp; United States; On-site; USD 140,000 - 190,000; Full time

Job summary

SumUp is seeking a software engineer to strengthen the Merchant Risk Intelligence team. You will develop Go-based backend services, contribute to our risk decision framework, and help design scalable distributed systems.

Collaboration with data scientists, ML engineers, fraud strategy, and product managers will be central to turning complex problems into practical, secure solutions. You will also contribute to Python initiatives, apply AI-assisted tooling, and participate in code reviews and

Qualifications

• Professional experience developing software with Go/Golang.
• Experience building and operating distributed systems and backend services.
• Strong system design skills and an understanding of reliable, maintainable software architecture.
• Experience working with Kubernetes and Kafka.
• Working knowledge of Python and an interest in contributing to Python-based products or AI/agentic development.
• Experience using AI-assisted tools as part of your software development workflow.
• Experience working in agile, cross-functional teams and collaborating with stakeholders beyond engineering.
• A pragmatic, outcome-focused approach: define an MVP, make sensible trade-offs and improve iteratively.

Responsibilities

• Develop new functionality and support existing services across the tribe’s codebase, primarily using Go
• Contribute to the continued development of our in-house merchant risk decision framework, taking it beyond its MVP and enabling new fraud prevention, risk and compliance use cases
• Design, build and maintain reliable distributed systems and backend services
• Work closely with product managers, data scientists, machine learning engineers, fraud strategy teams and operational stakeholders to turn complex problems into practical solutions
• Help shape technical direction, service boundaries and system design decisions across the team
• Contribute to Python projects, including AI-agent initiatives, as you build a broader understanding of the team’s systems
• Participate in code reviews, testing, monitoring and continuous improvement of production services
• Use AI-assisted development tools thoughtfully to deliver meaningful features faster without compromising code quality, security or maintainability
• Be open to participating in an on-call rotation as the team’s production responsibilities and support model evolve

Skills

Go

Distributed systems

System design

Agile teams

Python knowledge

AI-assisted development

Tools

Kubernetes

Kafka

Job description

SumUp is seeking a software engineer to strengthen the Merchant Risk Intelligence team. You will develop Go-based backend services, contribute to our risk decision framework, and help design scalable distributed systems.

Collaboration with data scientists, ML engineers, fraud strategy, and product managers will be central to turning complex problems into practical, secure solutions. You will also contribute to Python initiatives, apply AI-assisted tooling, and participate in code reviews and