Senior Backend Engineer, Global Accounts

About SumUp

At SumUp, we empower small businesses worldwide with simple, affordable tools to start, run, and grow. Over 4 million merchants across 37 markets trust us as their financial partner. We are a global team of 3,000+ individuals from over 90 nationalities, united by curiosity, collaboration, and care. Our core values and culture shape everything we do, fostering inclusion, learning, and belonging.

The Global Bank Tribe

Within the Global Bank tribe, we are building the infrastructure to provide merchants with a digital business account that empowers them to manage their banking needs. Our ambition is to become the most popular banking partner for small merchants globally, offering an effortless, simple, and affordable experience. You will help us transition from fragmented regional setups to a unified global infrastructure, directly enabling millions of merchants worldwide.

About the Role

As a Senior Backend Engineer on the Global Accounts team, you will own critical components of our bank account platform. You will help design and build a fully distributed, event-driven system engineered for scalability across regions, with resilience and compliance embedded from the start. You'll work primarily in Kotlin, with opportunities in Elixir and Golang. We practice Extreme Programming: small iterations, daily deliveries, and a strong focus on technical design quality and deep problem understanding.

Our tech stack includes Kotlin, Golang, Elixir, Java, AWS, Kafka, PostgreSQL, and Kubernetes, supported by observability tools like Prometheus, Grafana, and Honeycomb. We also leverage AI-assisted development tools such as Cursor and GitHub Copilot.

What You'll Do

• Build Critical Infrastructure from Scratch: Contribute to the design and implementation of a newly architected global accounts platform. Migrate existing systems to a modern, event-driven, decoupled architecture that enables scalability and resilience across regions.
• Master Event-Driven Architecture: Work extensively with Kafka to build a truly decoupled, resilient system. Event-driven architecture is fundamental to our goal of ensuring that failures in one part of the system do not impact banking operations globally.
• Solve Complex Compliance Challenges: Design flexible systems that accommodate varying regulatory and verification requirements across different regions and use cases, making compliance maintainable and integrated rather than an afterthought.
• Enable Other Teams: Build a self-service platform that empowers internal teams across the organization to contribute to and build upon.
• Work Globally: Your contributions will directly impact EU and LATAM markets, with potential US expansion on the horizon.

You'll Be Great for This Role If You Have:

• Strong Technical Foundation: Solid backend development experience in Kotlin, with an interest in working across multiple languages (Golang, Elixir). You understand system architecture, object-oriented and functional design principles, data modeling, and API design (RESTful and event-driven).
• Event-Driven Architecture Expertise: Proven experience with Kafka and event-driven systems. You understand how this enables true decoupling and resilience in distributed systems.
• Distributed Systems Mastery: Experience building, testing, observing, scaling, and ensuring the robustness and fault tolerance of distributed systems. Hands-on experience with AWS, Docker, Kubernetes, cloud-native architectures, and relational databases, with an understanding of data consistency and performance.
• Ownership and Craft: Full ownership of the software you ship, from design to production readiness. A commitment to clean, maintainable code and continuous refactoring for simplicity and scalability.
• Motivated by the Challenge: Curiosity and energy for complex problem-solving, thriving in environments with fast iterations and careful design where deep problem understanding is valued. Excitement about architecting critical systems from scratch and practicing Extreme Programming with daily deliveries.
• Collaborative Mindset: Respectful communication, open knowledge sharing, and active support for teammates' growth.

Why You'll Enjoy Working at SumUp

• Be part of a company that values diversity and celebrates unique perspectives.
• Work with a global team of skilled professionals in an environment that fosters collaboration, learning, and growth.
• Contribute to building a banking solution from the ground up, delivering impactful solutions to millions of SumUp merchants.
• Career Growth & Learning: Regular training, mentorship programs, SumUp University leadership cohort, and a yearly learning budget (2,000 EUR).
• Sabbatical Program: For tenured SumUppers.
• Global Team & Belonging: Participate in D&I initiatives and Employee Resource Groups (Pride Club, SumAfro, Neurodiversity, Grupos Mais, Women in Tech, etc.).
• Health & Wellness: In-house fitness classes, gym access, subsidized Urban Sports Club, and psychotherapy sessions.
• Other Benefits: Subsidized Public Transport Card, Kita placement assistance, Pension Scheme, Language Learning platform/courses.
• Virtual Stock Ownership Program: Own a stake in SumUp's future success.

About SumUp

SumUp empowers small businesses worldwide with simple, affordable tools. Over 4 million merchants in 37 markets trust us. We are a global team of 3,000+ from over 90 nationalities, united by curiosity, collaboration, and care. Our core values and culture shape everything we do, fostering inclusion, learning, and belonging.

SumUp is a proud Equal Employment Opportunity employer, committed to building a safe, respectful, and diverse workplace where everyone can thrive.

Job Application Tip: We encourage you to apply even if you don't meet 100% of the job criteria; we value room for learning and development.