AI Applied Scientist

About Marshmallow

We build financial products that accelerate the economic freedom for people who move across borders. We started with car insurance — insuring over a million drivers — and we’re scaling beyond. Tens of millions of people move countries each year, facing overlooked financial challenges. Our future is in building financial products around their needs to positively impact their lives.

How We Work

We’re really proud of the culture we’ve created. We push for progress every day, because we know that we’ll only hit big milestones by taking lots of smaller steps. We’re always open to helping our team mates, sharing our ideas, experience and knowledge to solve problems together. We take risks, think creatively and experiment relentlessly to meet our customer’s needs, and never pass blame when things go wrong. We encourage people at all levels to take ownership of their work, and to be bold in challenging how we do things. Everyone has a voice and the opportunity to make an impact.

And autonomy and ownership are only possible with clear direction. That’s why we collaborate to do in-depth planning twice a year, and make sure we leave with clear goals and objectives that flow from top to bottom. To make sure we’re as aligned as possible across functions, most of our work rolls up into three tribes; Acquisition, Retention & Claims. Each tribe has multiple teams embedded in it, working cross-functionally to do great work.

We’re so excited for all of the challenges up ahead, and we need more people to help us tackle them! If life at Marshmallow sounds like it could be for you, explore our Culture Handbook to find out more.

AI & Automation at Marshmallow

Our AI & Automation team is at the forefront of transforming how we engage with our customers by building intelligent, agentic AI solutions that enhance customer interactions and operational efficiency. This team plays a critical role within the Retention tribe, focusing on delivering cutting-edge conversational AI technologies that support complex, high-stakes customer journeys such as policy renewals and retention negotiations.

The team works closely with cross-functional partners across Product, Operations, Finance, and senior leadership to ensure AI-driven solutions are robust, compliant, and aligned with Marshmallow’s strategic goals.

Joining this team means being part of a fast-moving, innovative environment where curiosity, collaboration, and continuous learning are essential. You’ll help shape the future of AI-powered customer experiences in a regulated industry, tackling unique challenges that require both technical expertise and strong communication skills to bridge the gap between technology and business.

Role Description

As an AI Applied Scientist at Marshmallow, you will lead the development and refinement of customer-facing AI agent solutions, focusing on implementing and enhancing conversational AI through our Sierra platform. Your role bridges data science and AI application, driving the evolution of high-performing, robust systems that deliver complex, real-world interactions such as retention negotiations and personalised customer engagement. You will collaborate across teams to translate cutting-edge AI capabilities into practical, regulated solutions that improve customer experience and operational efficiency, while helping to shape the future of AI-driven financial products at Marshmallow.

What you'll be doing

• Lead the design, development, and implementation of customer-facing AI agent solutions.
• Develop and refine conversational AI models to achieve human-equivalent performance in complex customer interactions.
• Establish and maintain robust evaluation frameworks and monitoring systems to ensure AI quality, compliance, and regulatory standards.
• Drive experimentation and iterative improvement cycles to enhance AI agent capabilities and customer experience.
• Own the end-to-end lifecycle of AI agent deployments, including prompt design, context management, and troubleshooting to optimise conversational flow.
• Collaborate closely with cross-functional teams, acting as a technical bridge, communicating complex AI concepts clearly to both technical teams and senior leadership.
  
  

Who are you?

• You are deeply curious and passionate about the fast-evolving field of AI, especially in customer-facing generative AI and conversational agents.
• You thrive in a dynamic, exploratory environment and are motivated by solving complex, high-stakes problems that have real-world impact.
• You communicate complex technical concepts clearly and effectively to both technical and non-technical stakeholders, bridging gaps in understanding.
• You take ownership and pride in building robust, high-performing AI systems that deliver measurable value and improve customer experiences.
• You are comfortable navigating ambiguity and can design thoughtful experimentation frameworks to iterate and improve AI-driven customer journeys.
• You are enthusiastic about being a key voice in shaping the future of AI applications within the company and beyond, helping to build internal knowledge and capabilities.
  
  

Essential Experiences

• Proven experience working with customer-facing generative AI or conversational AI solutions.
• Strong background in data science with hands-on experience deploying and evaluating machine learning or AI models, particularly large language models (LLMs).
• Deep understanding of prompt engineering, LLM evaluation, and agentic AI systems, with the ability to design and optimize conversational flows
• Experience working with or integrating third-party AI platforms (e.g., Sierra) and collaborating with external technology partners.
• Solid SQL skills for data querying and analysis to support model evaluation and experimentation frameworks.
• Excellent communication skills with the ability to translate complex technical concepts to non-technical stakeholders and senior leadership.
  
  

Perks of the job

• Flexi-office working – Spend 2-3 days a week with your team in our new collaborative London office. The rest is up to you!
• Competitive bonus scheme - designed to reward and recognise high performance
• Flexible benefits budget - £50 per month to spend on a Ben Mastercard, meaning you get your own benefits budget to spend on things you want. Whether that’s subscriptions, night classes (puppy yoga, anyone?), the big shop or a forest of houseplants. Pretty much anything goes
• Sabbatical Leave - Get a 4-week fully paid sabbatical after being with us for 4 years
• Work From Anywhere - 4 weeks work from anywhere to use, with no need to come to the office
• Mental wellbeing support – Access therapy and mental health sessions through Oliva
• Learning and development – Personal budgets for books and training courses to help you grow in your role. Plus 2 days a year - on us! - to further your skillset
• Private health care - Enjoy all the benefits Vitality has to offer, including reduced gym memberships and discounts on smartwatches
• Medical cash plan - To help you with the costs of dental, optical and physio (plus more!)
• Tech scheme - Get the latest tech for less
  
  

Plus all the rest; 33 days holiday, pension, cycle to work scheme, monthly team socials and company-wide socials every month!

Our process

We Break It Up Into a Few Stages

• Initial call with our Talent Acquisition Partner - 30 mins
• A past experience interview where you will discuss your journey so far and ways of working with Hannah, our hiring manager - 60 mins
• A technical interview with a couple of the team - 60 mins
• A culture interview with a bar raiser to see if your work style fits our processes and values (and vice versa!) - 60 mins
  
  

Everyone belongs at Marshmallow

At Marshmallow, we want to hire people from all walks of life with the passion and skills needed to help us achieve our company mission. To do that, we're committed to hiring without judgement, prejudice or bias.

We encourage everyone to apply for our open roles. Gender identity, race, ethnicity, sexual orientation, age or background does not affect how we process job applications.

We're working hard to build an inclusive culture that empowers our people to do their best work, have fun and feel that they belong.

Recruitment privacy policy

We take privacy seriously here at Marshmallow. Our Recruitment privacy notice explains how we process and handle your personal data. To find out more please view it here.