Senior Full-Stack Engineer - SuperApp

Role overview

As a full-stack web engineer on the SuperApp squad, you will take end-to-end responsibility for key parts of the merchant experience across web, Android, and iOS. Your work will directly influence the everyday tools used by millions of small business owners to manage and grow their businesses. This position offers broad ownership, the chance to shape technical choices, and a direct impact on product quality for SumUp’s web experience.

What you will do

• Take ownership of major web dashboard capabilities, including the onboarding experience, homepage widgets, quick actions, the tools area, and the communications hub.
• Develop and support backend services that enable these user journeys, while keeping the experience aligned across web and mobile platforms.
• Partner with iOS and Android developers, product managers, and designers to create joined-up cross-platform solutions and influence technical direction.
• Drive technical design and improvement work by documenting solutions clearly, making architectural choices, and keeping stakeholders informed on progress.
• Contribute actively to the web chapter and help strengthen the wider engineering culture at SumUp.

Requirements

• Hands-on experience building production-grade applications with React.js and TypeScript, with an emphasis on scalability and maintainability.
• Comfort working across the stack, including backend services or REST APIs; experience with Go is beneficial, while Node.js or comparable technologies are also acceptable.
• Ability to work through and improve complex codebases while maintaining clean code practices and strong system design thinking.
• Experience collaborating in cross-functional teams with product and design, along with a high degree of ownership and comfort operating in ambiguous situations.
• A product-focused mindset that connects engineering choices to merchant needs and business results.

What makes this role attractive

• Work from SumUp’s Berlin office in an office-first setup and contribute to large-scale fintech products used by businesses around the world.
• Be part of an organisation that actively supports diversity, inclusion, and respect for different perspectives.
• Join the Virtual Stock Option programme and take a stake in SumUp’s long-term success.
• Receive an annual learning and development budget of €2000 for conferences, training, or further education.
• Benefit from a corporate pension plan with company matching of up to 20% of your contributions.
• Enjoy 28 days of paid leave in addition to public holidays and special leave days.
• Access additional benefits such as an Urban Sports Club subsidy, assistance with Kita placement, and subsidised office lunches.
• Qualify for Break4me, a 1-month sabbatical after 3 years of service.
• Earn a referral bonus for bringing talented people into the team.

About SumUp

SumUp’s mission is to help small businesses around the world succeed by giving them simple, affordable tools for payments, financing, and customer relationships. More than 4 million businesses across 37 markets use SumUp today. The company has a global team of over 3,000 people representing more than 90 nationalities, and it places strong emphasis on inclusion, learning, and a supportive environment where everyone can belong and grow.

Equal opportunity and workplace standards

SumUp is an equal opportunity employer and does not base hiring or employment decisions on race, colour, religion or religious belief, ethnic or national origin, nationality, sex, gender, gender identity, sexual orientation, disability, age, or any other protected characteristic. The company also maintains a strict no-harassment policy and is committed to providing a safe, respectful workplace for everyone.

Application guidance

Candidates are encouraged to apply even if they do not match every requirement. The company views the listed criteria as a guide for growth rather than a strict checklist, and it welcomes applicants who are eager to learn and develop further.

Additional notes

The role is based in Berlin and follows an office-first working model. The position is focused on the merchant experience across web and mobile platforms, with significant ownership of both frontend and backend work.