About the team

​​You have probably used our card readers to buy a cappuccino or pay your hairdresser already. In Hardware, we are passionate about creating these beautifully designed card payment devices and accessories that enable our merchants to start, run, and grow their own businesses. In doing so, we deal with a diverse range of engineering topics - industrial and electronic design, embedded systems, all the way to mobile apps and backend services.

We believe in open communication and constant learning over strict rules. If you're looking for the chance to innovate and help millions of small independent merchants succeed - join us!

Curious to know how it feels working in the Hardware team? Check this out!

About the role

As a Senior Backend Engineer, you will support the team with delivering new features for our payment devices. You will also be maintaining existing features such as  transaction flows for different payment methods, firmware updates, and other integrations with our internal services. You will help in maintaining our terminal backend, which includes assets management, card payment processing, hardware configuration, logging and monitoring.

As a Senior Backend Engineer, you will be part of one of our small and highly skilled cross-functional teams and work together with Product Managers, Mobile Engineers (iOS and Android), Product Designers, Embedded Engineers, and more.

To be successful in this role you should be open to constantly learning and improving your craft. You enjoy collaboration with others, particularly in a cross-functional setup and you’re also open to contribute to technical discussions and express your opinions openly. 

What you’ll do

• Implement, and iteratively improve backend services implemented with Elixir
• Participate in API design and implementation for both internal APIs and those exposed to our devices,mobile application and other clients
• Help your team to deliver business value by taking decisions related to backend and actively participating in the product discussions
• Provide comprehensive documentation, good test coverage,improve code quality, security and services observability
• Collaborate with other Software, QA and DevOps engineers to ensure smooth deployment, continuous integration, and support for the software that we deliver
• Constantly look for and chase the opportunities to automate and improve continuous integration and deployment pipelines
• Actively participate in code reviews with other software engineers 
• Our tech stack includes:Elixir, OTP, Postgres, Redis, Docker

You’ll be great for this role if:

• You have experience as a backend engineer.
• You have experience with Elixir and OTP.
• You’ve worked on RESTful APIs.
• You’ve experience working with Postgres.
• You have a good understanding of software architecture and application design.
• You have a passion for clean, maintainable and testable code
• You are humble, transparent and enjoy working with the people around you.
• You are proactive and able to thrive in a fast-paced, dynamic environment.

Why you should join SumUp 

• Opportunity to work with a truly global, multicultural team (we are 3200+ people from 80+ countries, spread across 4 continents).
• 28 days’ paid leave
• Competitive salary package and virtual stock option programme
• Learning & development budget for attending conferences and external training
• SumUp Corporate Pension Scheme
• Wellness benefits: in-house Yoga teacher, gym in the office, football & running teams, subsidized Urban Sports Club
• A lot of other cool benefits such as Bike leasing, Subsidised Public Transport Card, Language Learning platform/courses, Kita placement assistance, relocation assistance, 2x per week subsidised office lunches, and a brand new beautiful place to work in the heart of Berlin!

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.