Senior Machine Learning Engineer II - SumUp

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+ ye