Fullstack Engineer

SumUp gives small businesses the tools they need to get paid, manage their money, and grow - today, over 4 million merchants across 37 markets worldwide rely on SumUp to do exactly that.

The Bank Web squad sits within SumUp's Bank domain and owns the web experience across our banking surfaces - from the business account dashboard that merchants use daily, to the back-office tooling that powers the support teams behind them. The team has a clear mission: make Bank Web a genuinely first-class platform, on par with our mobile applications in quality, reliability, and performance.

Joining now means being part of a team that’s at a key growth point - modernization work, growing scope across markets, and making architectural decisions that will shape how millions of merchants experience SumUp's banking products.

👉 Take a look at our Sofia office

What you'll do

• Build and own features end-to-end across our web banking surfaces - from scoping and component implementation through testing, observability, and production maintenance
• Work across the full stack - including defining API contracts, working with backend proxies, and integrating with the services that power our banking platform
• Contribute to modernisation efforts, including architectural improvements, component refactoring, and stack migrations that reduce technical debt and accelerate future delivery
• Review peers' pull requests with attention to UI consistency, accessibility, and frontend best practices
• Participate in production support and incident reviews, helping to strengthen the squad's operational resilience across its web domain

You'll be great for this role if…

• Strong experience with React, TypeScript, with a track record of delivering production-ready features end-to-end -not just isolated UI components
• Genuine full-stack capability: Experience defining API contracts, working with backend proxies, and owning integrations, not just consuming them; backend experience in Node, Kotlin, Java, or Golang is valued
• Solid understanding of frontend architecture, component design patterns, state management, and how frontend applications connect to backend services
• Experience writing and maintaining frontend tests (unit, integration, snapshot, end-to-end) and a genuine care for code quality and reliability
• Comfort navigating a complex, multi-stack codebase. React and TypeScript are core to this role, while our broader ecosystem also includes Node.js, Kotlin, Java, Go, Angular, AWS and Kafka. Prior experience with all of these is not required, but familiarity with most of them is a plus
• Curiosity about complex domains - banking products have intricate user flows and edge cases, and you enjoy digging into them to find the right solution
• Familiarity with CI/CD practices and getting changes safely to production; exposure to AI tooling to augment engineering workflows is a plus

Why you should join SumUp

• 🌍 Opportunity to work with SumUppers globally on large-scale fintech products used by millions of businesses worldwide, from our modern Sofia 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 and 10 paid days of educational leave which can be used to attend conferences and/or advance your career through further education
• 🏖️ Generous time off: 25 days of paid leave, plus one extra day per year of service (up to 35), along with public holidays and special leave options
• 🏥 Peace of mind: additional health insurance and life insurance
• 💪 Stay active: on-site yoga and a co-sponsored Multisport card offering access to hundreds of sports facilities
• 🍽️ Meal support: benefit from a tax-free food voucher program plus flexibility via our Re:Benefits platform
• 🚌 Easy commute: free shuttle buses connecting directly to Joliot-Curie metro station
• 🌴 Break4me: 1-month sabbatical after 3 years of service
• 🔗 Referral Bonus: earn additional rewards by referring talented individuals to join the SumUp team

About SumUp

Be empowered to do more that matters.

At SumUp, we're on a mission to empower small businesses across the globe by providing simple and affordable tools that allow them to thrive. Today, over 4 million businesses in 37 markets rely on SumUp as their financial partner to manage payments, finance and customer relationships.

Our commitment to small businesses is reflected in our diverse team of over 3,000 SumUppers from over 90 nationalities, united by global collaboration and an innovative mindset. Our core values lay the foundation for who we are and what we stand for, shaping our work culture and driving our success. We foster inclusivity and a continuous learning culture, providing a safe space for personal and professional growth. Our differences make us unique and strong as we strive to create an environment where everyone belongs and feels supported, no matter how they identify.

SumUp is proud to be an Equal Employment Opportunity employer, actively seeking and embracing diversity in our workforce. We don't make hiring or employment decisions based on race, colour, religion or religious belief, ethnic or national origin, nationality, sex, gender, gender identity, sexual orientation, disability, age or any other basis protected by applicable laws or prohibited by company policy. Our commitment extends beyond recruitment to creating a safe and respectful workplace where harassment of any form is strictly prohibited. Discover more about our culture and opportunities on our careers website, and follow our journey on LinkedIn, Instagram, and TikTok.

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.