---
title: 'Backend Engineer - Cards at SumUp'
canonical: 'https://feeny.ai/job/backend-engineer-cards-sumup-sofia-84ymebpe4899'
type: 'job'
last_seen: '2026-09-08'
---

# Backend Engineer - Cards at SumUp

- **Company:** SumUp
- **Location:** Sofia, Bulgaria
- **Posted:** 2026-06-09
- **Last confirmed live:** 2026-09-08
- **Apply:** https://sumup.com/careers/positions/8583427002?gh_jid=8583427002

## Job description

SumUp builds simple, affordable financial tools that help small businesses get paid, manage their money, and grow. Beyond payments, we offer a number of financial products - including business banking, card products, lending, and invoicing — giving merchants everything they need to manage their payments and finances in one place.

The Cards squad is a core part of that, owning the systems that power card issuing, lifecycle management, and transaction processing for merchants across Europe. We handle millions of card transactions every day, and we're now scaling those systems to support new product capabilities while laying the foundations for a more global, resilient platform. That's why we're growing the team and looking for a seasoned backend engineer who can take real ownership of complex, high-impact work. If you want to build systems that genuinely matter to small businesses and you're excited by the technical depth that comes with high-throughput, distributed architecture, this is the role for you.

🎥 Join us in our Sofia Team - get a feel for our Sofia office [here](https://youtu.be/gqtjm5NUXs0?si=t7YARvQWQHHidD_z).

## What you'll do

- Own and lead the end-to-end delivery of backend services within the Cards EU domain, including observability, testing, and production support
- Contribute to the technical roadmap by participating in architectural discussions and proposing solutions for complex, distributed systems challenges
- Raise well-scoped pull requests, conduct thorough code reviews, and help maintain high standards of code quality and test coverage across the team
- Collaborate closely with engineers in adjacent squads and with the product manager to shape and refine the squad backlog
- Participate in incident reviews and the on-call rotation, taking accountability for the reliability of the services you build
- Apply and champion AI tooling to accelerate engineering workflows, and help raise the team's overall AI literacy

You'll be great for this role if…

- Solid, hands-on experience delivering production-ready backend services end-to-end, including testing, monitoring, and maintenance, on a modern cloud-native stack
- Production experience with Kotlin and an openness to work with additional languages such as Elixir, Java or Golang.
- Solid understanding of distributed systems, API design, data modelling, and working with relational databases
- Hands on experience in containerisation, orchestration, and CI/CD practices
- Ability to take an ambiguous product problem, define the technical approach, and lead it through to implementation with minimal guidance
- Comfort working across teams and communicating clearly in written and spoken English in a professional setting
- Genuine curiosity about the product domain — comfortable applying a backend lens during feature refinement and thinking beyond the code to understand how your work shapes the user experience

## 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](https://youtu.be/9DG64C3moeQ?si=YpcWuBNBTOQPzeLI) of over 3,000 SumUppers from over 90 nationalities, united by global collaboration and an innovative mindset. [Our core values](https://www.sumup.com/careers/culture/) 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](https://www.sumup.com/careers/), and follow our journey on [LinkedIn](https://www.linkedin.com/company/sumup/), [Instagram](https://www.instagram.com/insidesumup/), and [TikTok](https://www.tiktok.com/@insidesumup). 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.

## About SumUp

## Company Overview
- **One-liner**: SumUp is a global fintech company that provides simple, affordable payment and financial management tools to help small businesses start, run, and grow.
- **Entity Type**: Private (Funding stage not publicly available)
- **Headquarters**: London, United Kingdom
- **Founded**: 2012
- **Founders**: Not specified in provided sources

## Core Business
- **Primary industry**: Financial Services / Fintech (Payments)
- **Target customers**: Small and medium-sized businesses (SMBs), B2B
- **Mission or purpose statement**: "Empower small businesses all over the world." — with the vision of "a world where everyone can build a thriving business."

## Products & Services
- **Payment Processing (Card Readers & POS)**: Hardware and software solutions for in-person and online payments, enabling merchants to accept card and contactless payments.
- **SumUp Business Account**: A digital business account for managing finances and transactions.
- **Invoicing & Customer Relationship Tools**: Tools to create invoices, manage customers, and streamline operations.

## Market Standing
- **Valuation/Market Cap**: Not disclosed (private company)
- **Key Metric**: Over 4 million merchants served across 37 markets; 3,000+ employees from more than 90 nationalities
- **Notable Investors/Partners**: Not listed in provided sources
- **Growth Signals**: Headcount growth to 3,000+; recognition as a Top Global Employer for inclusion (Stonewall Workplace Equality Index 2022/2023) and Fintech Diversity Initiative of the Year (2025); expansion across 4 continents with 20+ offices.

## Competitive Advantages
- **Global reach**: Operating in 37 markets with localized products and support.
- **Merchant focus**: Deep commitment to small business owners, with products designed specifically for their needs.
- **Inclusive culture**: Strong diversity and inclusion programs, gender parity in workforce, and employee-led communities (e.g., Pride Club).
- **Autonomous teams**: Small, empowered teams with servant leadership, fostering innovation and speed.

## Strategic Focus
- Expanding product and service portfolio to become a complete financial partner for small businesses.
- Continuing to invest in a learning culture (SumUp University) and employee development.
- Maintaining an office-first culture while enabling occasional remote work to balance collaboration and flexibility.
- Growing market presence by entering new geographies and deepening existing ones.

## Why Work Here
- **Culture**: Office-first company that values human connection, autonomy, and continuous learning. Core values include Team First, We Care, and Founder’s Mentality.
- **Remote/Hybrid policy**: Office-first with the ability to work remotely occasionally, as agreed with teams.
- **Benefits**: Relocation support for overseas hires, dedicated budget for conferences and external training, and location-specific perks.
- **Engineering culture**: Autonomous teams, servant leadership, and a focus on pragmatic, self-driven problem-solving.
- **Inclusion**: Recognized as a Top Global Employer for inclusion; active LGBTQ+ community and gender parity initiatives.
- **Hiring process**: Transparent, with recruiter screening, hiring manager interview, technical assessment, team interview, bar raiser, and final offer.

## Sources
1. [sumup.com](https://www.sumup.com/careers/)
2. [linkedin.com](https://www.linkedin.com/company/sumup)
3. [sumup.com](https://www.sumup.com/careers/culture/)
4. [sumup.com](https://www.sumup.com/careers/positions/)
5. [sumup.com](https://www.sumup.com/careers/how-we-hire/)

## Other roles at SumUp

- [Business Development Manager - North Dublin/Meath](https://feeny.ai/job/business-development-manager-north-dublin-meath-sumup-dublin-tt3gp9ymv2z7) — Dublin, Ireland
- [Field Sales Executive](https://feeny.ai/job/field-sales-executive-sumup-louth-gagq165z2h6c) — Louth, Ireland
- [Field Sales Executive](https://feeny.ai/job/field-sales-executive-sumup-meath-316t843a6cw3) — Meath, Ireland
- [Backend Engineer (Golang) - Bank Balance](https://feeny.ai/job/backend-engineer-golang-bank-balance-sumup-vilnius-pebbxc1jrtty) — Vilnius, Lithuania
- [(Senior) Backend Engineer (Golang) - Bank](https://feeny.ai/job/senior-backend-engineer-golang-bank-sumup-vilnius-d4s1c64bwbr9) — Vilnius, Lithuania
- [Backend Engineer (Golang) - Bank Balance](https://feeny.ai/job/backend-engineer-golang-bank-balance-sumup-berlin-9wry4wjw3rng) — Berlin, Germany
- [Senior Backend Engineer](https://feeny.ai/job/senior-backend-engineer-sumup-london-england-9r9bgnz6t1sm) — London England, United Kingdom
- [Executivo(a) de Vendas Externas | Taubaté - SP](https://feeny.ai/job/executivo-a-de-vendas-externas-taubate-sp-sumup-taubate-sao-paulo-vmfyqg8xxdt8) — Taubaté São Paulo, Brazil
- [Executivo(a) de Vendas Externas - Santo Antônio de Jesus, Bahia](https://feeny.ai/job/executivo-a-de-vendas-externas-santo-antonio-de-jesus-bahia-sumup-santo-antonio-s599zj39m7nb) — Santo Antônio de Jesus Bahia, Brazil
- [Senior Treasury Analyst (Corporate Treasury)](https://feeny.ai/job/senior-treasury-analyst-corporate-treasury-sumup-sao-paulo-sao-paulo-c8tx86b1tn26) — São Paulo São Paulo, Brazil