Full Stack Engineer

Sumup

Our Billing and Subscriptions team sits at the heart of how SumUp's merchants pay for, manage, and grow with our products. We own the billing engine, merchant wallet, and subscription experiences that underpin millions of transactions across 37 markets, and right now, we're in an exciting phase of rebuilding and expanding that foundation. We're deepening our billing capabilities to support new sales models, market expansions, and financial integrations that directly shape how small businesses experience SumUp — and this role is central to making that happen. What you'll do * Build and maintain backend services and frontend interfaces across our billing, contracts, and merchant wallet products * Contribute to the refactoring of key billing components to improve reliability, data security, and alignment with our wider payments platform * Support the expansion of our billing and wallet capabilities into new markets, helping ensure localisation requirements are met * Take part in our weekly support rotation, handling incoming customer queries and helping maintain platform stability * Work closely with senior engineers and product managers to deliver features end-to-end, from implementation through to production You'll be great for this role if * Solid experience building full stack applications, with a backend focus. Ideally comfortable with Node.js or Go, though we're open to other backend languages. * Comfortable working with both relational databases such as PostgreSQL or MySQL and non-relational databases (such as DynamoDB, MongoDB, or Redis). * Practical frontend experience working with React and Next.js, with the ability to write clean, typed code in TypeScript or JavaScript. * Strong communication skills in English, both written and spoken, with the ability to give and receive clear, constructive feedback. * A pragmatic approach to problem-solving, able to make sensible trade-offs, unblock yourself and others, and write clean, maintainable code. Why you should join SumUp * 🌎 Opportunity to work with SumUppers globally on large-scale fintech products used by millions of businesses worldwide, from our Berlin office. This involves an office-first setup * 🌈 Commitment to Diversity and Inclusion: be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced * 📚 A dedicated annual L&D budget of €2000 for your individual development, which can be used to attend conferences and/or advance your career through further education * 💶 A corporate pension scheme where we match up to 20% of your contributions * 🏖 Generous time off: enjoy 28 days of paid leave plus public holidays and special leave days * 🏙 Numerous other benefits such as Urban Sports Club subsidy, Kita placement assistance, subsidised office lunches * 🌴 Break4me: 1-month sabbatical after 3 years of service * 🔗 Referral Bonus: earn additional rewards by referring talented individuals to join the SumUp team About SumUp Be empowered to do more that matters. 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 lay the foundation for who we are and what we stand for, shaping our work culture and driving our success. We foster inclusivity and a continuous learning culture, providing a safe space for personal and professional growth. Our differences make us unique and strong as we strive to create an environment where everyone belongs and feels supported, no matter how they identify. SumUp is proud to be an Equal Employment Opportunity employer, actively seeking and embracing diversity in our workforce. We don't make hiring or employment decisions based on 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. Our commitment extends beyond recruitment to creating a safe and respectful workplace where harassment of any form is strictly prohibited. Discover more about our culture and opportunities on our careers website, and follow our journey on LinkedIn, Instagram, and TikTok. Job Application Tip We recognise that candidates feel they need to meet 100% of the job criteria in order to apply for a job. Please note that this is only a guide. If you don’t tick every box, it’s ok too because it means you have room to learn and develop your career at SumUp.

Prior Labs

WHO WE ARE Foundation models transformed text and images. Structured data - the largest and most consequential data format in the world - stayed untouched. Tables run every clinical trial, every financial model, every scientific experiment, every business decision, and no one had built a foundation model that truly understood them. Until now. What LLMs did for language, we're doing for tables. The next modality shift in AI is happening, and we're hiring the team that makes it. Momentum. We pioneered tabular foundation models and are now the world-leading organization in structured-data ML. Our TabPFN v2 model was published as a Nature cover story and set a new state of the art for tabular machine learning. Since release we've scaled model capabilities 20x+, passed 3.5M+ downloads and 7,500+ GitHub stars, and are seeing accelerating adoption across research and industry - from detecting lung disease with Oxford Cancer Analytics to preventing train failures with Hitachi to improving clinical-trial decisions with BostonGene. The hardest work is ahead. We're scaling tabular foundation models to millions of rows, thousands of features, real-time inference, and entirely new data modalities, while building the infrastructure to run them in production across some of the most demanding industries on earth. These are open problems no one else is working on at this level. Our team. We're a small, highly selective team of 30+ engineers, researchers, and GTM specialists, with backgrounds spanning Google, Apple, Amazon, DeepMind, Meta, Microsoft Research, G-Research, Jane Street, Goldman Sachs, and CERN. We're led by Frank Hutter, Noah Hollmann, and Sauraj Gambhir, and advised by world-leading AI researchers including Bernhard Schölkopf and Turing Award winner Yann LeCun. We ship fast, do top-tier research, and hold each other to an extremely high bar. What's next. In 2025 we raised €9m pre-seed led by Balderton Capital, backed by leaders from Hugging Face, DeepMind, and Black Forest Labs. The next phase of growth is here, which makes this an ideal time to join. ABOUT THE ROLE We’re looking for exceptional engineers to help build the ML Platform that powers our tabular foundation model line. This is a unique chance to work at the intersection of data science, agents, UX, and real-world economic impact. You'll work on the product end-to-end: frontend, backend, and everything in between. What you'll work on: * Build the core platform that puts tabular foundation models into users' hands — from data upload and exploration through inference and results * Architect reliable, low-latency backend services that handle real-time model inference at scale * Work directly with the research team to turn new model capabilities into production features * Own the frontend experience for technical users (data scientists, ML engineers) who have high expectations and low tolerance for friction You may be a good fit if you have: * 3+ years building highly-available, user-facing products across the full stack, with real ownership of what shipped * Experience building data-intensive applications (dashboards, analytics tools, data exploration interfaces, or similar) * Strong JavaScript/TypeScript and Python — you're genuinely good at both, not just passable in one * Good product instincts — you think about what the user actually needs, not just what the ticket says * Comfort working close to ML systems, even if you're not training models yourself — you understand model inputs, outputs, and failure modes well enough to build reliable interfaces around them * Enthusiasm for working in a fast-moving, ambiguous environment where new ideas ship quickly and user impact matters most Bonus: * Cloud infrastructure experience (GCP preferred) * Background building developer tools, data platforms, or ML-adjacent products * Experience with React, FastAPI, and Postgres (our current stack) Life at Prior Labs We're a small, ambitious team solving one of the hardest problems in AI, and we're just getting started. You'll work closely with world-class researchers and builders who care deeply about the quality of their craft, the impact of their work, and the people they work with. We move fast, we think rigorously, and we take the time to do things right. If you're excited by hard problems, motivated by real-world impact, and want to be part of building something that matters, we'd love to hear from you. We're building our teams in Berlin, Freiburg, and New York and we believe that when you're working on something as hard and exciting as TabPFN, being in the same room matters. Most of our roles are based in one of our offices but great people come from everywhere, and in exceptional cases we're open to remote. This usually involves frequent travel to one of our offices and the whole company comes together regularly for offsites to think, build, and celebrate together. Our Commitments We believe the best products and teams come from a wide range of perspectives, experiences, and backgrounds. That's why we welcome applications from people of all identities and walks of life, especially anyone who's ever felt discouraged by "not checking every box." We're committed to creating a safe, inclusive environment and providing equal opportunities regardless of gender, sexual orientation, origin, disability, or any other trait that makes you who you are. We care about how your data is handled. Read our Recruiting Privacy Notice to see exactly what we collect, why, and how long we keep it.

Sumup

The Sidekick team builds and owns the progressive web app that SumUps field sales agents rely on every day, a tool that brings together everything a seller needs in one place: creating offers on the go, signing up new merchants, managing hardware sales, and tracking commissions in real time. It's one of our most impactful internal products, sitting at the heart of a primary revenue driver for the business. As our Senior Full Stack Engineer, you'll take genuine ownership of features end-to-end, from scoping through to production, working closely with product, engaging directly with sales stakeholders, and having a real say in what gets built and why. If you want autonomy, meaningful scope, and work that directly enables the people driving SumUp's growth, this is the role. What you'll do * Build and maintain features across the full stack of our progressive web app, spanning the field sales experience, back office tooling for sales agents, and emerging LLM-powered support tooling, owning work from scoping through to production * Participate actively in product discovery, joining user research sessions, reviewing usage data, and contributing to prioritisation discussions alongside product * Work directly with sales stakeholders to understand their needs, distinguish between what's requested and what's actually needed, and propose solutions with clear trade-offs * Contribute to raising engineering standards across the team, through documentation, code quality, and proactive process improvements * Integrate with external systems such as Salesforce where required, and help shape how data flows across domains to create a consistent experience for field sellers You'll be great for this role if * Hands-on experience with a full-stack framework, Next.js, Remix, Nuxt, or similar, 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 a production environment. * Experience building or consuming RESTful APIs and working within complex micro service systems, familiarity with Go is welcome. * Comfortable as a Kubernetes user, with exposure to working in cloud-native, distributed environments. * Experience working in a product-led or dual-track agile team alongside our product 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 for ways to simplify or automate where it makes sense. Why you should join SumUp: * 🌎 Opportunity to work with SumUppers globally on large-scale fintech products used by millions of businesses worldwide, from our Berlin office. This involves an office-first setup * 🌈 Commitment to Diversity and Inclusion: be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced * 🚀 Enrolment onto our Virtual Stock Option programme: you will own a stake in SumUp's future success * 📚 A dedicated annual L&D budget of €2000 for your individual development, which can be used to attend conferences and/or advance your career through further education * 💶 A corporate pension scheme where we match up to 20% of your contributions * 🏖️ Generous time off: enjoy 28 days of paid leave plus public holidays and special leave days * 🏋️ Numerous other benefits such as Urban Sports Club subsidy, Kita placement assistance, subsidised office lunches * 🌴 Break4me: 1-month sabbatical after 3 years of service * 🔗 Referral Bonus: earn additional rewards by referring talented individuals to join the SumUp team About SumUp Be empowered to do more that matters. 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 lay the foundation for who we are and what we stand for, shaping our work culture and driving our success. We foster inclusivity and a continuous learning culture, providing a safe space for personal and professional growth. Our differences make us unique and strong as we strive to create an environment where everyone belongs and feels supported, no matter how they identify. SumUp is proud to be an Equal Employment Opportunity employer, actively seeking and embracing diversity in our workforce. We don't make hiring or employment decisions based on 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. Our commitment extends beyond recruitment to creating a safe and respectful workplace where harassment of any form is strictly prohibited. Discover more about our culture and opportunities on our careers website, and follow our journey on LinkedIn, Instagram, and TikTok Job Application Tip We recognise that candidates feel they need to meet 100% of the job criteria in order to apply for a job. Please note that this is only a guide. If you don’t tick every box, it’s ok too because it means you have room to learn and develop your career at SumUp. Job Application Tip We recognise that candidates feel they need to meet 100% of the job criteria in order to apply for a job. Please note that this is only a guide. If you don’t tick every box, it’s ok too because it means you have room to learn and develop your career at SumUp.