Backend Engineer (Golang) - Balance Management

SumUp; Berlin (NH); On-site; USD 120,000 - 180,000; Full time

Job summary

SumUp's Global Bank team is building core infrastructure to give merchants a digital banking experience. As a Backend Engineer, you'll modernize systems, support a global platform, and collaborate with teams across regions to enable consistent and reliable financial services.

You'll work with Golang, Kotlin/Elixir as needed, deploy on AWS with Docker and Kubernetes, and focus on high-volume, compliant services.

Qualifications

• Solid backend experience delivering reliable, high-volume services with thoughtful system design.
• Proficient in Golang; comfortable with Kotlin or Elixir as needed.
• Write maintainable, well-tested code with CI/CD practices and ownership from dev to prod.

Responsibilities

• Build and evolve core banking services transforming regional systems into a global platform.
• Tackle distributed systems challenges ensuring resilience under high transaction volumes.
• Improve observability, expand test coverage, refactor for maintainability, and introduce scalable patterns.
• Contribute to architectural decisions—ledger and transaction history systems for global use.
• Collaborate with Risk, Treasury, Finance, and Infrastructure to ensure compliant operations.
• Own services from design to production, monitor performance, and continuously improve delivery.

Skills

Backend development

Golang

Kotlin

Elixir

CI/CD

Docker

Kubernetes

AWS

PostgreSQL

System design

Testing

Tools

Kafka

PostgreSQL

Grafana

Honeycomb

Job description

At SumUp, theGlobal Bank team builds the core infrastructure and services that give merchants a digital bank account, helping small businesses manage their money easily and reliably.

The Balance Management Squad sits at the core of the Global Bank Platform. Right now, our team is completing a major milestone: consolidating and modernizing our balance management system in Europe. The next big step is creating a global transaction history service; a single, shared platform used by all regions to give merchants consistent and transparent views of their financial activity.

As a Backend Engineer, you'll help modernize existing systems while balancing innovation with stability, collaborate with teams across regions, and build reliable services that manage diverse markets with different regulations.

If you enjoy solving complex problems on high-load systems, are curious about banking, and are looking for a team that tackles challenges head-on, we'd love to hear from you.

What You'll Do

• Build and evolve the SumUp's core banking services that powers ledger operations and transactions, transforming our regional systems into a unified, scalable global platform.
• Tackle complex distributed systems challenges, ensuring resilient services that continue to perform under high transaction volumes.
• Support modernization initiatives by improving observability, adding test coverage, refactoring code for long-term maintainability, and gradually introducing new architectural patterns without disrupting live banking operations.
• Contribute to key architectural decisions - build ledger and transaction history systems from the ground up, ensuring a globally scalable banking solution for our clients.
• Collaborate with teams across Risk, Treasury, Finance, and Infrastructure to ensure smooth, compliant, and reliable global operations
• Take ownership from design to production, running the services you build, monitoring their performance, and continuously improving how we deliver high-quality software at scale.

You'll be great for this role if

• You have solid backend experience building reliable, high-volume services and you think carefully about system design, APIs, data modeling, and how services interact.
• You are proficient in Golang and comfortable learning and working with other languages as needed, e.g. Kotlin or Elixir.
• You write maintainable, well-tested code, follow CI/CD best practices, and take responsibility for the software you build from development to production.
• You're comfortable building, deploying, and running services in cloud environments like AWS using Docker and Kubernetes.
• You're eager to learn about relational databases that perform well under load and maintain data consistency.
• You are a collaborator who enjoys working across regions, communicating clearly, exchanging feedback effectively, and making thoughtful technical decisions together.
• You have a curiosity for building reliable financial services and banking domain

It's a plus if you have

• Knowledge of Elixir - some of our legacy services are written in Elixir, and while it's not essential, it would be useful if you've worked with it before
• Deeper PostgreSQL experience - we rely heavily on Postgres, so if you've done performance tuning, complex queries, or schema design, that's a plus
• Experience with event streaming platforms (Kafka preferred) and modern observability stacks (Grafana, Honeycomb, etc.)

Why you should join 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.
• Be part of a global tribe building a banking solution from the ground up and delivering impactful solutions to the real-life problems of millions of SumUp merchants all over the world
• Career growth and learning opportunities: We invest in your development through regular training, mentorship programs, SumUp University leadership cohort and a yearly learning budget (2,000 EUR)
• Sabbatical program for tenured SumUppers
• Join a global team where you belong: Check out our D&I Initiatives and Employee Resource Groups such as Pride Club, SumAfro, Neurodiversity, Grupos Mais, Women in Tech, and more
• Health & wellness benefits: in-house fitness classes, gym in the office, subsidized Urban Sports Club and available psychotherapy sessions
• A lot of other benefits such as Subsidized Public Transport Card, Kita placement assistance, Pension Scheme, Language Learning platform/courses etc.
• Enrollment onto our virtual stock ownership program - you will own a stake in SumUp's future success

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 a vast set of simple and affordable business tools to help them start, run, and grow their businesses. Today, over 4 million businesses in 36 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 3,000 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 an inclusivity and 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 employment decisions based on race, colour, religion or religious belief, ethnic or national origin, nationality, sex, gender, gender identity, sexual orientation, disability, age or any other basis protected by applicable laws or prohibited by company policy. Our commitment extends beyond recruitment to creating a safe and respectful workplace where harassment of any form is strictly prohibited.

Explore career opportunities with us and join a team driven by collaboration, innovation, and a shared vision of creating a world where everyone can build a thriving business. Discover more about our vibrant and inclusive work culture and how we work on our careers website, and follow our journey on LinkedIn and Instagram.

Job Application Tip

We recognise that candidates feel they need to meet 100% of the job criteria in order to apply for a job. Please note that this is only a guide. If you don't tick every box, it's ok too because it means you have room to learn and develop your career at SumUp.