Senior Full Stack Engineer - Sidekick
The Sidekick team builds and owns the progressive web app that SumUp's field sales agents rely on every day, bringing together creating offers on the go, signing up new merchants, managing hardware sales, and tracking commissions in real time. It is one of SumUp's most impactful internal products and sits at the heart of a primary revenue driver. As a Senior Full Stack Engineer, you will take genuine end-to-end ownership of features, work closely with product, and engage directly with sales stakeholders, based in Berlin.
Responsibilities
- ▹Build and maintain features across the full stack of the progressive web app, spanning the field sales experience, back office tooling, and emerging LLM-powered support tooling, from scoping through to production
- ▹Participate actively in product discovery, joining user research sessions, reviewing usage data, and contributing to prioritisation discussions
- ▹Work directly with sales stakeholders to understand their needs, distinguish requests from actual needs, and propose solutions with clear trade-offs
- ▹Contribute to raising engineering standards through documentation, code quality, and proactive process improvements
- ▹Integrate with external systems such as Salesforce and help shape how data flows across domains
Requirements
- ▹Hands-on experience with a full-stack framework such as Next.js, Remix, or Nuxt, with a clear track record of shipping real-world features end-to-end
- ▹Strong, proven experience with React and TypeScript, building scalable, maintainable applications in production
- ▹Experience building or consuming RESTful APIs and working within complex microservice systems
- ▹Comfortable as a Kubernetes user, with exposure to cloud-native, distributed environments
- ▹Experience in a product-led or dual-track agile team, contributing to product decisions, not just technical ones
- ▹A natural tendency to reach out to stakeholders, ask the right questions, and bring genuine empathy to the end user's experience
- ▹Comfortable showcasing and demoing work, and always looking to simplify or automate
Nice to have
- ▹Familiarity with Go
Soft skills
What we offer
- ▹Virtual Stock Option programme, giving a stake in SumUp's future success
- ▹Dedicated annual L&D budget of EUR 2000
- ▹Corporate pension scheme with matching up to 20% of contributions
- ▹28 days of paid leave plus public holidays and special leave days
- ▹Additional benefits such as Urban Sports Club subsidy, Kita placement assistance, and subsidised office lunches
- ▹1-month sabbatical after 3 years of service (Break4me)
- ▹Referral bonus
About the company
SumUp is a global fintech company on a mission to empower small businesses with simple, affordable tools for payments, finance, and customer relationships. Over 4 million businesses across 37 markets rely on SumUp, and its team numbers more than 3,000 people from over 90 nationalities.