(Senior) Backend Engineer - Balance Management
In SumUp's Global Bank team, the Balance Management Squad sits at the core of the Global Bank Platform, powering ledger operations and transactions. The team is completing the consolidation and modernization of the European balance management system and building a global transaction history service that gives merchants consistent, transparent views of their financial activity. As a Backend Engineer, you'll modernize existing systems while balancing innovation with stability and build reliable services for markets with different regulations.
Responsibilities
- ▹Build and evolve SumUp's core banking services that power ledger operations and transactions, transforming regional systems into a unified, scalable global platform
- ▹Tackle complex distributed systems challenges, ensuring resilient services that perform under high transaction volumes
- ▹Support modernization by improving observability, adding test coverage, refactoring code and gradually introducing new architectural patterns without disrupting live operations
- ▹Contribute to key architectural decisions and build ledger and transaction history systems from the ground up
- ▹Collaborate with Risk, Treasury, Finance and Infrastructure teams for smooth, compliant global operations
- ▹Take ownership from design to production, running and monitoring the services you build
Requirements
- ▹Solid backend experience building reliable, high-volume services with careful attention to system design, APIs, data modeling and service interaction
- ▹Proficiency in Golang and comfort learning other languages as needed (e.g. Kotlin or Elixir)
- ▹Ability to write maintainable, well-tested code following CI/CD best practices and take responsibility from development to production
- ▹Comfort building, deploying and running services in cloud environments like AWS using Docker and Kubernetes
- ▹Eagerness to learn about relational databases that perform well under load and maintain data consistency
- ▹A collaborative approach with clear communication and thoughtful joint technical decisions
- ▹Curiosity for building reliable financial services and the banking domain
Nice to have
- ▹Knowledge of Elixir (some legacy services are written in it)
- ▹Deeper PostgreSQL experience such as performance tuning, complex queries or schema design
- ▹Experience with event streaming platforms (Kafka preferred) and modern observability stacks (Grafana, Honeycomb, etc.)
Soft skills
What we offer
- ▹25 days of paid leave plus 1 additional day for each year of employment
- ▹Up to 10 days of educational leave
- ▹Regular training, mentorship programs, SumUp University leadership cohort and a yearly learning budget (2,000 EUR)
- ▹Virtual stock ownership program - a stake in SumUp's success
- ▹SumUp Sabbatical and an employee assistance program for mental health
- ▹Additional health insurance, subsidized Multisport card, free shuttle buses from Joliot-Curie metro station and global offsites and/or hackathons
About the company
At SumUp, over 4 million businesses in 36 markets rely on the company as their financial partner to manage payments, finance and customer relationships. It is a diverse team of over 3,000 people from over 90 nationalities that fosters an inclusive, continuous-learning culture.