Senior Backend Engineer

Jackalope Digital LLC; Greater London; Hybrid; GBP 90,000 - 140,000; Full time

Benefits offered by this job

Private health insurance

Virtual Stock Option programme

28 days paid leave

L&D budget for conferences & training

Retirement scheme with company match

Life insurance

1-month sabbatical after 3 years

Referral bonus

Salary-sacrifice commuter benefits

Job summary

SumUp is seeking a backend engineer to own and advance core neobanking services, including transfers, open banking, and payments. You will shape architecture, drive end-to-end delivery, and ensure reliability in a fintech environment.

The role focuses on Go/Kotlin/Python and working with AWS, Docker, and Kubernetes to build scalable, production-grade systems. You’ll collaborate with product, design, data science, security and operations to ship impactful features from ideation to live deployment.

Qualifications

• Strong proficiency in Go, Kotlin or Python with production-grade backend experience.
• Experience with cloud platforms (AWS) and container orchestration (Docker, Kubernetes).
• Solid understanding of SQL and NoSQL databases and high-availability trade-offs.

Responsibilities

• Build and maintain Backend services for Core neobanking features including bank transfers, open banking, savings accounts, and payment processing.
• Take end-to-end ownership of features from design to deployment and maintenance, using Go with Docker/Kubernetes.
• Lead architectural discussions, implement best practices in testing, automation, and security.

Skills

Go

Kotlin

Python

AWS

Docker

Kubernetes

SQL

NoSQL

High availability

Job description

About the team

At SumUp, we're on a mission to bring merchants and consumers closer together and help local communities thrive. Within the Consumer Mission, we're building a rewarding banking experience that connects people to the small businesses they love while tackling some of the most technically demanding challenges in fintech: critical infrastructure migrations, smooth, uninterrupted payment experiences, seamless open banking integrations, and high‑availability banking systems that can’t afford to fail – all while enabling free transactions for our merchants.

This role sits at the heart of that work — you’ll take real ownership of backend services that are close to our consumers, directly shaping their everyday experience, with impact that’s visible and felt across the entire platform.

What you'll do

• Build and maintain Backend services for Core neobanking features including bank transfers, open banking, savings accounts, and payment processing
• Take end-to-end ownership of features and projects, covering scoping, design, development, testing, deployment, and maintenance, leveraging Go along with Docker and Kubernetes for container orchestration.
• Take ownership of critical infrastructure migrations — including our banking core system transitions — without disrupting live customer experiences
• Collaborate closely with cross-functional teams including product, design, data science, security, and operations) to understand requirements, provide technical insights, and contribute to architecture discussions that ship meaningful banking features end-to-end
• Support fellow developers and actively help build a collaborative, innovative engineering culture
• Shape technical architecture and lead code reviews, helping define and promote best practices in code quality, testing, automation, and security to raise the overall engineering bar.
• Build and integrate tools and systems that improve operational efficiency and reliability, with strong observability through monitoring, alerting, and hands‑on involvement in incident response and post‑mortems.

You'll be great for this role if you have…

• Strong proficiency in Go, Kotlin or Python, with a track record of building scalable, production-grade backend services
• Experience working with cloud platforms (AWS or comparable) and container orchestration tools such as Docker and Kubernetes
• Solid understanding of SQL and NoSQL databases, distributed systems, and the trade-offs that come with high-availability requirements
• Comfort navigating complex, regulated environments — whether that's financial services, payments, or similarly high-stakes domains
• A collaborative, product-oriented mindset with the ability to work independently, communicate clearly, and adapt when priorities shift

Any of the following would be considered a plus

• Previous experience in a Growth-focused engineering team.
• Familiarity with the Fintech or Banking regulatory landscape.

No visa sponsorship available with this position

Why you should join SumUp

• Opportunity to work with a truly global, multicultural team from our central London Bridge location. 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
• Generous time off: enjoy 28 days of paid leave, plus bank holidays and special leaves
• A dedicated annual L&D budget for attending conferences and/or advancing your career through further education
• Health matters: private health insurance, including optical and dental
• Life made easier: salary-sacrifice commuter benefits via Gogeta
• Financial security: retirement scheme (SumUp matches 7% when you contribute 5%)
• Peace of mind: life insurance from MetLife for 2× your salary
• 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 Want to bring this role to life visually? Check out our Global Employer Brand video library to add a video to your job post or create LinkedIn content.

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.

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