Senior Backend Engineer - Golang

The Commercial Systems and Intelligence squad is a newly formed team building the infrastructure that powers how SumUp attributes merchant acquisition, calculates commissions, and understands the full lifecycle of every merchant. You'll join at the very beginning, helping to shape how the squad works, the architecture it builds on, and the standards it holds itself to.

What you'll do

• Aggregating data from across the SumUp ecosystem to determine which acquisition channel or sales agent drove a merchant to take a valuable action (e.g. signing up, adopting a product)
• Establishing data models, API contracts, and rule definitions that automate existing manual commission workflows for field and tele-sales agents, partnerships and merchant referrals
• Build the Lifecycle Event Log in close collaboration with the Merchant Intelligence squad. A centralized store of curated merchant lifecycle events (signups, product usage, verification, purchases) used across attribution, recommendations, customer support and sales
• Build internal backoffices and APIs for sales representatives and leaders to monitor commission and modify commission plans, manage portfolios and resolve disputes
• Define and document API contracts, schemas, and integration patterns that other engineering teams can adopt confidently
• Establish best practices for testing, observability, and incident response within a newly formed squad

What you'll need

• Strong backend engineering background in Go, or typed-language generalist ready to ramp up quickly
• Experience designing APIs and distributed systems with clear contracts, versioning, and integration patterns
• Fluency in relational and analytical databases (PostgreSQL, Snowflake)
• Experience building Kafka-based, event-driven systems and understanding event sourcing and CDC patterns
• Experience in auditable, high-trust systems where every decision must be traceable — fintech, payments, or similar domains
• Ability to bridge technical and non-technical audiences, translating fuzzy problems into clear engineering work
• Mentorship instincts; you raise the bar for the people around you

What they offer

• Annual L&D budget of €2,000 for conferences and further education
• VSOP program: equity stake in SumUp's future success
• Corporate pension scheme with up to 20% company match
• 30 days sabbatical after 3 years of employment
• Urban Sports Club subsidy, Kita placement assistance, relocation assistance, subsidised office lunches
• Hack Days every second Friday and global Hack Weeks