SumUp Accelerator – Fullstack Engineering Intern

Build AI-powered products that impact millions of small businesses.

At SumUp, we build fintech solutions that empower over 4 million merchants across 37 markets to run and grow their businesses. Every day, this generates rich payments and business data, and SumUp's next-gen AI tools turn that data into practical insights and intelligent tools that create real merchant value.

This is not a traditional internship. From day one, you'll join a product squad, contribute to shared codebases, and ship production code used by merchants every day.

Location: Central London
Duration: 3 months, starting 15th June (full time) 
Starting Salary: £32,500  

Curious what that actually looks like? Watch how our Accelerator participants become contributors to real-world features at SumUp.

What You'll Work On

You'll contribute to greenfield products, significant internal tools, and groundbreaking new technologies being integrated into the SumUp ecosystem — with a focus on:

• Backend & Fullstack engineering (APIs, services, dashboards)
• AI-enabled backend systems and data pipelines
• User-facing services and UI/UX

Your Impact

Working alongside experienced engineers, data scientists, and product managers, you will:

• Build end-to-end product features for SumUp's AI Initiative, from backend APIs and data pipelines to user-facing services
• Integrate with core SumUp systems, databases, and internal tooling
• Write clean, testable, well-documented code following team standards
• Participate fully in team rituals: planning, technical discussions, code reviews, and knowledge-sharing sessions
• Take ownership, iterate quickly on ideas and prototypes, and learn by shipping real features

You Might Be a Great Fit If You…

• Are a recent graduate (Bachelor's or Master's), final year student, or early-career professional (0–2 years' experience) in Computer Science, Software Engineering, or a related field
• Understand data structures, algorithms, and object-oriented programming
• Have hands-on experience with at least one modern language,  Python, Go, Java, Kotlin, or JavaScript preferred
• Are familiar with Git and collaborative workflows (branches, pull requests)
• Understand client-server architecture and HTTP fundamentals
• Can write simple SQL queries and understand how data is structured and accessed
• Are curious about AI, data, and how technology creates real merchant value
• Learn fast, welcome feedback, and enjoy working in collaborative cross-functional teams

Why Join SumUp?

Impact with Purpose - Ship products used by millions of small businesses while building next-gen AI tools. This isn't a sandbox.

Come As You Are — A workplace that celebrates diversity and fosters an inclusion-first culture.

Office Perks — Complimentary breakfast every Wednesday and lunch on Thursdays.

Team Culture — Regular social events to connect and unwind.

About SumUp

Be empowered to build things that matter.

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 and