Senior AI/ML Engineer

At SumUp, we are motivated by the purpose of levelling the playing field for small businesses. We empower small business owners by creating simple and affordable tools to manage payments, finance and customer relationships. We are a passionate team that thrives on human connection, autonomy and the desire to constantly learn, guided by our values: Founder’s Mentality, Team First, and We Care. We want to build an enduring organisation that is people-positive, disciplined and that constantly innovates from within. Agility is the essence of an enduring organisation and we strive to create an organisation that fosters it.

In Global Operations, we build the best customer experience in fintech. The Senior AI/ML Engineer role is critical for developing and deploying the next generation of AI-driven solutions that automate support and drastically improve the experience for both our merchants and support agents. You will be a key expert who builds and maintains the ML infrastructure and tooling that powers our core products using advanced AI/ML models. This role is a replacement, essential for maintaining momentum as we expand complex use cases like our AI Assistant and translation tools.

What You'll Be Doing

• You will be the dedicated technical leader for the Operations AI team, focused on designing, developing, and deploying high-performance, scalable ML/AI solutions in production environments.
• Architect, design, develop, and deploy our AI solutions and systems into production environments, ensuring reliability, high performance, and scalability.
• Take ownership and technical leadership in the development and maintenance of main AI products, including the AI Assistant (automating ~40% of merchant requests), AI Translation (enabling cross-language agent service), and the AI Agent Copilot.
• Develop and maintain ML infrastructure and pipelines to support efficient data processing, model training, serving, and continuous monitoring.
• Optimise and fine-tune machine learning models, and collect, preprocess, and clean large text datasets to ensure high-quality input for model training and evaluation.
• Embrace software development principles, best practices, and industry standards, including version control (Git), CI/CD processes (GitHub actions), and unit testing frameworks.
• Collaborate closely with Data Scientists, Product Managers, Developers, and other business stakeholders to enhance customer experience and improve operational efficiency globally.
• Complex Onboarding: Rapidly master a large, existing AI assistant infrastructure, starting immediately with working on behaviour improvements and agentic rollouts.
• Pilot and Innovation: Lead the creation of the pilot for the Voice Assistant and design how to leverage current AI assistant components to empower new channels.

You’ll Be Great for This Position If You Have

• 7+ years of proven experience as a Machine Learning Engineer or AI Engineer, focusing on building and deploying scalable machine learning or AI solutions and data-driven systems.
• Expert-level Python proficiency and excellent software development engineering skills for designing computationally effective solutions in large-scale production.
• Strong previous experience as an ML or AI engineer, with models in production, and a strong understanding of artificial intelligence, machine learning, and deep learning concepts.
• Experience using GenAI / LLM API and experience evaluating LLM models in production.
• Experience building and deploying ML Models using Cloud platforms (AWS, GCP, or Azure).
• Familiarity with MLOps tools (e.g., MLFlow, Kubeflow, Airflow, Langfuse), and hands-on experience with Kubernetes, Git, and Airflow.
• Good understanding of data pipelines, API design, containers (Docker), and version control (Git).
• Experience building, maintaining, and scaling APIs, and deployment using CI/CD Pipelines in GitHub actions.
• A true team player attitude who thrives on cross-functional collaboration.
• Self-drive, proactiveness, and high adaptability in a fast-paced environment, with a commitment to data governance, quality, and ownership.
• A passion for AI Technology, excited to power SumUp's next generation of automated support tools, and able to translate complex concepts to non-technical stakeholders.

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 attending conferences and/or advancing 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

At SumUp, we’re on a mission to empower small businesses around the world with simple, affordable tools to help them start, run, and grow. More than 4 million merchants across 36 markets trust us as their financial partner — and we’re just getting started. We’re a global team of 3,000+ people from over 90 nationalities, united by curiosity, collaboration, and care. Our core values and culture shape everything we do, fostering inclusion, learning, and belonging.

SumUp is proud to be an Equal Employment Opportunity employer, committed to building a safe, respectful, and diverse workplace where everyone can thrive.

👉 Explore more about our culture on our careers site, or follow us on LinkedIn and Instagram.