Senior Fullstack Engineer - Onboarding

Location: Sofia, in-office 

We are looking for a Senior Fullstack Engineer to join our Onboarding squad. In this role, you will have a decisive impact on enhancing our Onboarding Platform, contributing to both the backend systems and the web dashboard that drive the onboarding funnel. You’ll focus on building scalable, maintainable systems while ensuring the seamless integration of Auto KYB (Know Your Business) and Auto KYC (Know Your Customer) processes. These automated systems are essential for compliance and risk management, verifying the identity and legitimacy of businesses and individuals during merchant onboarding.

You will take ownership of system design, resolve technical ambiguities, and set high standards for code quality and architecture. Additionally, you’ll lead cross-team projects, addressing systemic challenges and driving innovation strategically impacting our business goals. Beyond technical contributions, you’ll serve as a mentor and thought leader, fostering a culture of collaboration, trust, and continuous learning across the organization.

This is a unique opportunity to shape our engineering practices, contribute to key strategic initiatives, and directly influence the growth and success of our platform.

What you’ll do: 

• Design, develop, and enhance the Onboarding Platform, focusing on both backend services (mostly Java) and the web dashboard (mostly JavaScript/TypeScript)
• Implement scalable, maintainable solutions that seamlessly integrate Auto KYB and Auto KYC processes into the onboarding flow
• Lead cross-team/tribe initiatives, establish and uphold high standards for code quality, system architecture, and documentation
• Collaborate with stakeholders across engineering, product, and compliance to align technical efforts with business goals
• Mentor and guide team members, fostering a culture of trust, collaboration, and continuous learning across the squad and beyond

You’ll be great for this position if you have:

• 6+ years of experience in full-stack development with a proven track record of delivering high-quality applications
• Strong expertise in the JVM ecosystem with deep knowledge of Java and related frameworks and tools
• Experience with JavaScript and/or TypeScript
• Hands-on experience with distributed systems and microservices architectures, including designing and managing scalable services
• Operational experience with Kubernetes and containerization tools, with a solid understanding of deployment and orchestration best practices
• Adept at working with new and legacy systems, including transitioning and integrating legacy applications with modern technologies

Why you should join SumUp

• You’ll play a key role in a scale-up that in turn is part of a truly global team of 3000+ people from 60+ countries, spread across 4 continents
• You'll have the opportunity to make an impact irrespective of your job description. You'll have the space to drive your career and take ownership of projects
• You’ll receive 25 days’ paid leave, increasing with tenure, and paid vacation for certain occasions. You’ll enjoy a paid 1 month Sabbatical vacation 
• You’ll receive an individual learning budget and can take 10 days educational leave to expand your skillset
• You’ll have monthly digital food vouchers 
• You’ll have monthly budget for a wide choice of benefits and discounts ranging from transport, food, learning and many more (re:benefit platform) 
• You’ll have access to an attractive referral program
• You'll enjoy other great benefits such as additional health and life insurance; funded therapy & coaching sessions with licensed psychotherapists; co-sponsored Multisport card; child birth/adoption bonus; free shuttle buses from Joliot-Curie metro station; a long list of discounts and more 

About us

SumUp is a leading financial technology company, founded in 2012 with the goal of empowering small businesses around the globe. We’re the financial partner of choice for more than 4 million merchants in over 35 markets. We collectively build, plan and fine-tune the technology that drives SumUp and empowers small businesses around the world.

We believe in the everyday hero. Those who have the courage to follow their passion and who have the strength and determination to realise their dreams. Small business owners are at the heart of all we do, so we're creating powerful, easy-to-use financial solutions to help them run their business. With a founders mentality and a 'team-first attitude' our diverse teams across Europe, South America, and the United States work together to ensure that small business owners 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.