← Back to list
Job

Software Engineer (Golang) - Online Payments

SumUp
Backend Developer • On-site • Full-time • 📍 Sofia
📄 View original listing (EN)

SumUp's Online Payments team, part of the Payments Tribe based in Sofia, processes billions of transactions across 36+ countries and handles all Card Not Present (CNP) online payments. As a backend engineer you will co-create and improve the Golang-based microservices platform, focusing on scalability and high availability. The team works in autonomous, cross-functional, co-located squads that own their part of the platform end-to-end.

Stack

AWSDockerGoJavaKafkaKotlinKubernetesLinuxPostgreSQLPython

Responsibilities

  • ▹Co-design and develop high-performance, secure backend services for the Online Payments Platform
  • ▹Participate in API design and implementation for internal and external integrations
  • ▹Deliver business value through backend decisions and active participation in product discussions
  • ▹Ensure high code quality, comprehensive test coverage, and clear documentation
  • ▹Optimize application performance and scalability through active monitoring and proactive solutions
  • ▹Collaborate closely with software developers, QA, and DevOps engineers for smooth deployment, CI and support
  • ▹Actively participate in code reviews

Requirements

  • ▹Solid experience as a backend software engineer in any modern language (e.g. Go, Java, Python, Kotlin)
  • ▹Experience with PostgreSQL/RDBMS and distributed, fault-tolerant systems
  • ▹Genuine passion for clean, maintainable, and testable code
  • ▹Interest in using AI as part of the development workflow
  • ▹Good understanding of software architecture and application design

Nice to have

  • ▹Experience with Docker and/or Kubernetes
  • ▹Experience with Kafka or other messaging systems
  • ▹Experience with Unix/Linux environments
  • ▹DevOps practices (CI/CD)

Soft skills

Strong system design thinkingCollaborationOwnershipContinuous improvement mindset

What we offer

  • ▹€2,000 annual learning & development budget for conferences or education
  • ▹25 days of paid leave, increasing with tenure, plus paid vacation for special occasions
  • ▹1-month sabbatical every 3 years
  • ▹Health and life insurance
  • ▹Co-sponsored Multisport card
  • ▹Childbirth/adoption bonus and referral program
  • ▹€100 monthly food vouchers and €40 flexible benefits

About the company

SumUp is a leading financial technology company founded in 2012, serving more than 4 million merchants in over 35 markets. It builds simple, easy-to-use financial solutions for small businesses, with diverse teams across Europe, South America and the United States.