Backend Engineer - POS

SumUp's Point-of-Sale (POS) solution empowers cafes, shops, bars, hair salons, and other businesses to operate efficiently and grow. It offers a wide range of features, including product catalogs, inventory management, business analytics, compliance support, and loyalty tools.

As a Backend Engineer in the Orders & Sales or Catalog Platform team, you will build the engine powering core infrastructure for over 4 million businesses worldwide. Whether you are architecting global sales APIs or scaling item management systems, your work is central to the SumUp ecosystem.

The Orders & Sales team builds high-performance APIs and receipt engines that unify transaction and sales data, utilizing an AI-native mindset and extreme collaboration. Meanwhile, the Catalog Platform team owns the backend for item management, variants, categories, and taxes, focusing on high-stakes reliability and core POS infrastructure scaling. What you'll do

• Develop and evolve high-performance backend services and APIs using Kotlin and Spring Boot.
• Design and maintain robust data schemas and event-driven integrations (Kafka) to handle complex transaction and catalog data at scale.
• Write clean, well-tested, production-grade code and contribute meaningfully to code reviews and team rituals.
• Collaborate with mobile and product teams to ship end-to-end features with a focus on performance and data consistency.
• Engage in daily pair programming to solve complex concurrency challenges and maintain high architectural standards.
• Take full ownership of the development lifecycle, including managing CI/CD pipelines and monitoring service health in production.
• Actively use and experiment with AI coding agents to automate repetitive tasks and increase shipping velocity.
• Refactor and migrate mission-critical domain logic to centralize and simplify the "Sales" and "Catalog" experiences across the ecosystem.

• You have 3+ years of experience in backend engineering with the JVM stack (preferably Kotlin and Spring Boot).
• You have a solid understanding of software design patterns, data modeling, and fundamental system architecture principles.
• You are comfortable working with Kafka, Postgres, and AWS in a production environment at scale.
• You enjoy and actively seek out collaboration and daily pair programming as a primary way of working.
• You are an "AI-native" engineer, open to using agents and tools to optimize your coding process.
• You have experience with, or a strong interest in, distributed and fault-tolerant systems.
• You are a fast learner who values quality, detail, and effective time management.
• You are fluent in English and can communicate clearly with both technical and non-technical stakeholders.

Nice to have

• Experience with Kubernetes and cloud-native observability/monitoring tools.
• Knowledge of different programming paradigms (Functional vs. OOP).
• Familiarity with high-scale applications involving many concurrent processes.
• A desire to share knowledge with the wider engineering community.

Opportunity to work with SumUppers globally on large-scale fintech products used by millions of businesses worldwide, from our Berlin office. This involves an office-first setup

Commitment to Diversity and Inclusion: be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced

Enrolment onto our Virtual Stock Option programme: you will own a stake in SumUp's future success

A dedicated annual L&D budget of €2000 for your individual development, which you can be used to attend conferences and/or advancing your career through further education

A corporate pension scheme where we match up to 20% of your contributions

️ Generous time off: enjoy 28 days of paid leave plus public holidays and special leave days

️ Numerous other benefits such as Urban Sports Club subsidy, Kita placement assistance, subsidised office lunches