Principal Data Scientist

• Join Marshmallow, the UK unicorn insurtech and lender, in a full-time hybrid role in its London Data Science team. • Provide technical leadership for data science within Claims, one of Marshmallow’s most important customer touchpoints. • Shape the approach to risk decisioning and fraud detection across Claims Fraud. • Lead work across both traditional machine learning and Generative AI. • Help automate more of the claims journey by bringing system-level thinking to how decisioning scales. • Receive visa sponsorship for this position.

• Bring significant commercial experience delivering end-to-end machine learning solutions, from problem framing to production monitoring. • Show hands-on experience building and shipping Generative AI systems in production, not just prototypes. • Handle evaluation, safety and quality, and integration of GenAI into customer or operational workflows. • Bring a strong statistical and modelling foundation. • Show experience in risk-based decisioning under uncertainty, such as fraud, credit, insurance or other regulated domains. • Demonstrate proven ability to influence technical direction across Data Science and Engineering. • Shape scalable model and service integration patterns, and challenge proposals to drive long-term solutions. • Communicate trade-offs clearly and push back constructively with Product and Engineering. • Bring structure and momentum to complex, ambiguous problem spaces. • Commute to the London office 3 days a week.

• Bring experience working on insurance claims or claims fraud detection. • Show experience building monitoring, feedback loops or QA tooling for production AI systems. • Bring experience designing LLM evaluation frameworks for operational automation. • Show experience communicating model performance and uncertainty to senior stakeholders.

• Lead data science across Claims Fraud, shaping risk decisioning and fraud detection with Product and Engineering. • Design, build and iterate on production ML and Generative AI systems that support claims validation and automation. • Work with other Claims data scientists to improve how models, data and workflows fit together. • Identify architectural improvements that scale decisioning and reduce time-to-production. • Advocate for platform and tooling investments such as monitoring, feedback loops and QA to enable end-to-end claims automation. • Push for robust, scalable solutions that support the multi-year vision for automated claims handling. • Set a high bar for statistical rigour, experimentation and measurement. • Improve how Claims performance and uncertainty are communicated to senior stakeholders.

• Earn a bonus through a scheme designed to reward high performance. • Get private medical insurance with Vitality and mental health support with Oliva. • Use a personal learning budget and 2 dedicated L&D days a year. • Spend a monthly flexible benefits budget however you choose. • Enjoy 25 days’ holiday plus bank holidays. • Work from anywhere for 4 weeks a year. • Receive visa sponsorship for this role. • Work in a hybrid setup with 3 days a week in the London office.

Marshmallow started in 2017 with a mission to make migration easy, and has since grown from 3 to over 700 people. The company has reached unicorn status, raised around £140M across three funding rounds and become profitable, insuring millions of drivers and lending millions in car loans. It aims to become one of the largest financial services providers in the world by scaling existing products and building new ones.