Senior Backend Engineer (Golang)

Location: Sofia, in-office

The Verification Squad's goal is to integrate SumUp with external and internal sources to automate KYC processes. This ensures compliance with AML regulations, prevents fraud, and speeds up merchant onboarding. We focus on large-scale automated verification, partnering with top data and service providers for a fast, secure onboarding experience. Our work protects against fraud and helps small merchants worldwide accept payments safely.

As a Senior Backend Engineer (Golang), you'll help evolve and support our advanced platform, with a key challenge being the transition to a fully distributed, event-driven architecture.

What You’ll Do

• Collaborate with peers and stakeholders to design and build a unified global platform, including high-level APIs for multiple regions and local implementations, ensuring high availability and observability
• Build and maintain these highly available, self-healing, and resilient systems
• Support the migration of systems and processes, ensuring zero downtime for clients, and design, implement, and support high-value features for customers
• Improve test coverage for existing services and own the end-to-end delivery of changes, including testing, observability, and monitoring
• Continuously improve our engineering culture by refining best practices, clarifying problems and opportunities, prototyping solutions, providing comprehensive documentation and selecting new tools and technologies

You’ll be great for this role if you have

• Solid programming experience (5+ years) in Golang and are interested in working with additional languages such as Java, Kotlin and Ruby
• Extensive experience as a Backend Engineer specializing in distributed, fault-tolerant, and event-driven systems
• Proven experience in system design, data modeling, and API design
• Hands-on experience with Kafka, Postgres, SQL databases, and modern cloud technologies (AWS, Docker, Kubernetes)
• Experienced with CI/CD products such as GitHub Actions and ArgoCD
• You take pride in your work, have a keen sense of ownership, and are dedicated to writing clear, maintainable, and testable code
• Passionate about solving user challenges and improving products 
• Enjoy retiring old systems and challenging the status quo

Why you should join SumUp

• We’re a truly global team of 3000+ people from 80+ countries, spread across 4 continents
• You’ll receive 25 days’ paid leave, plus 1 additional day for each year of employment
• You can take up to 10 days’ educational leave to expand your skill set
• A dedicated annual Learning & Development budget (2000€ / year) for attending conferences and/or advancing your career through further education
• Enrollment onto our virtual stock ownership program - you will own a stake in SumUp’s future success
• Access to our Employee assistance program for mental health
• We offer additional health insurance and a subsidised Multisport card
• You’ll attend global offsites and/or hackathons

About the Growth Tribe

In the Growth Tribe our purpose is to grow SumUp's multi-product merchant base. 

We obsess about turning interested merchants into live merchants through offering an intuitive, trustworthy and cohesive experience from the first touch point on the marketing site to engaging with our products & services as they need them.

About SumUp

We believe in the everyday hero.

Small business owners are at the heart of all we do, so we create powerful, easy-to-use financial solutions to help them run their businesses. With a founder’s mentality and a 'team-first’ attitude, our diverse teams across Europe, South America and the United States work together to ensure that the small business owners we partner with can be successful doing what they love. 

SumUp is an Equal Employment Opportunity employer that proudly pursues and hires a diverse workforce. SumUp does not make hiring or employment decisions on the basis of 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. SumUp also strives for a healthy and safe workplace and strictly prohibits harassment of any kind.

SumUp will not accept unsolicited resumes from any source other than directly from a candidate.