SumUp Company Profile

Senior Backend Engineer Java Online Payments Platform


Munkaköri leírás

SumUp is a preferred provider for card payments solutions for millions of small and medium businesses across the world. We're now expanding our offering by developing a brand-new next gen online payments platform.

To achieve this, we're actively looking for software generalists with experience in online payments, who focus on solving problems, and see technology merely as a tool for it.

Although we are long past the start-up phase, we continue to work in fully autonomous teams, each driving their part of the product end-to-end.

On the tech side, we work on a number of different projects that span technologies, systems, and processes. A few of the technologies we're leveraging at SumUp include Java, Kotlin, Elixir, Ruby, Docker, Kubernetes, Redis, PostgreSQL.


  • Lay the foundations of our next generation payment platform
  • Develop modern scalable and highly available web and back-end applications
  • Participate in API design and implementation for both internal and external APIs
  • Own and maintain the business domain that your application touches
  • Implement clean, maintainable and testable code


  • You have vast experience with online payments/transaction processing systems that have high availability/throughput as a back-end engineer.
  • You have 5+ years' relevant experience in agile large scale ecosystems and first-hand experience in mentoring.
  • You have a solid understanding of design principles and designing clear and predictable REST APIs.
  • You have practical experience with relational databases or data-modelling
  • You have a DevOps mindset and interest in AWS, Docker, Kubernetes, and/or Jenkins and a quality-first approach.
  • You are familiar with engineering best practices to write clean quality code
  • You have vast experience with micro-services architecture, Restful APIs and operating in a cloud environment, especially AWS.
  • You are open to learning different tools, frameworks, and languages to get the job done.

If you don't meet the requirements 100%, we'd still love to hear from you.


  • You'll have the opportunity to build the foundations of our next generation payment platform.
  • You'll have the opportunity to make an impact as we work in flat hierarchies and with high autonomy.
  • You'll have the space to drive your career here and take ownership of projects.
  • You'll be part of a diverse and international team.
  • You'll attend global offsites/hackathons/team events.
  • You'll receive competitive compensation and have access to an education budget.
  • You'll receive 25 days paid vacation + 1 accumulative day for each year of employment at SumUp.
  • We offer additional health insurance, a subsidized Multisport card, free shuttle buses from Joliot-Curie metro station and other great benefits.
  • Innovative office design featuring an amazing 360 Sofia view, a music room, events forum space, fully equipped kitchen facilities; office relaxation activities such as yoga and massages.

You are welcome to have a look at developer documentation for online payments integrations: 

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