Senior AI Data Scientist

Tesco; Welwyn Garden City; Hybrid; GBP 70,000 - 100,000; Full time

Job summary

A leading UK retailer is seeking a Senior AI Data Scientist in Welwyn Garden City. The role involves building scalable solutions using advanced machine learning and generative AI. Key responsibilities include managing LLM systems, fostering a team-oriented environment, and driving customer growth. The candidate should have experience with AI evaluation methods, adept at guiding junior members, and comfortable in fast-paced settings with innovative problem-solving opportunities. Attractive benefits are offered, including a competitive bonus scheme and extensive time off.

Benefits

Annual bonus scheme of up to 20%

25 days of holiday plus personal day

Private medical insurance

24/7 virtual GP service

Qualifications

• Experience in managing context windows effectively.
• Strong experience in evaluating ML systems.
• Comfortable in a fast-paced environment.

Responsibilities

• Create new customer growth strategies.
• Design and ship production-grade LLM systems.
• Guide the team in fostering a culture of learning.

Skills

Practical experience applying LLMs

Understanding of LLM architectures

Evaluating data pipelines

Quantitative metrics for AI evaluation

Ability to explain complex concepts

Guiding junior team members

Influencing decision-making

Job description

# Senior AI Data ScientistTesco UK • Welwyn Garden City • Full-Time • Apply by 05-Jan-2026About the roleAt Tesco, our Data Science team builds scalable solutions to complex business challenges across stores, online, supply chain, marketing and Clubcard. We apply advanced machine learning, generative AI, and large language models (LLMs) to personalise customer experiences, optimise operations and drive innovation. We work across several business domains, including customer experience, online, fulfilment, distribution, commodities, store operations and technology. Team members rotate across domains to broaden their expertise and impact.We foster a culture of continuous learning, dedicating 10% of the working week to personal development. Our team benefits from academic partnerships, regular knowledge-sharing events and a collaborative, inclusive environment that values work-life balance and professional growth.What is in it for youWe’re all about the little helps. That’s why we make sure our Tesco colleague benefits package takes care of you – both in and out of work. to find out more!* Annual bonus scheme of up to 20% of base salary* Holiday starting at 25 days plus a personal day (plus Bank holidays)* Private medical insurance* 26 weeks maternity and adoption leave (after 1 years’ service) at full pay, followed by 13 weeks of Statutory Maternity Pay or Statutory Adoption Pay, we also offer 6 weeks fully paid paternity leave* Free 24/7 virtual GP service, Employee Assistance Programme (EAP) for you and your family, free access to a range of experts to support your mental wellbeingYou will be responsible forWe are seeking a Senior AI Data Scientist to operate within a fast-pacing team, to create new customer growth.Expect end‑to‑end ownership—rapid experimentation, fast shipping, and leaning in wherever the work takes you, beyond your job title. If you’re ambitious, hard‑working, and excited to build 0→1 against tall ambitions, you’ll thrive here.You will be designing and shipping production-grade LLM systems and shared platform capabilities that power experiences for millions, solving cross-cutting pain points with smart build‑vs‑buy decisions. You’ll work end‑to‑end—from rapid prototypes to production code—accelerating GenAI use cases across the business.While existing knowledge is valuable, a strong ability to learn quickly and apply new skills effectively is essential. The ideal candidate will be solution-oriented, eager to stay current with the latest developments, and comfortable in a fast-paced environment with ample room for creativity and problem-solving.You will need• Practical experience applying LLMs, including:o Managing context windows effectivelyo Selecting appropriate models for specific taskso Implementing safety guardrails and alignment techniqueso Decomposing complex tasks into model-friendly components• In-depth understanding of LLM architectures, training methodologies, and usage patterns.• Strong experience in evaluating and validating data pipelines and ML systems.• Familiarity with AI-specific evaluation methods, including both quantitative metrics and qualitative assessments.• Ability to make well-reasoned decisions grounded in technical understanding and real-world constraints.• Pragmatic approach to experimentation and solution design.• Proven ability to understand complex business challenges and translate them into actionable AI solutions.• Track record of explaining complex technical concepts in a clear, concise manner to non-technical audiences, including senior stakeholders and business leaders.• Experience guiding junior team members, fostering a culture of learning, and promoting best practices in AI.• Ability to work effectively with colleagues from diverse disciplines, such as software engineering, UX design, data analysis, product management, and business leadership.• Skilled at influencing decision-making and gaining buy-in, even in ambiguous or challenging environments.Our vision at Tesco is to become every customer's favourite way to shop, whether they are at home or out on the move. Our core purpose is ‘Serving our customers, communities and planet a little better every day’. Serving means more than a transactional relationship with our customers. It means acting as a responsible and sustainable business for all stakeholders, for the communities we are part of and for the planet.We are proud to have an inclusive culture at Tesco where everyone truly feels able to be themselves. At Tesco, we not only celebrate diversity, but recognise the value and opportunity it brings. We're committed to creating a workplace where differences are valued, and make sure that all colleagues are given the same opportunities. We’re proud to have been accredited Disability Confident Leader and we’re committed to providing a fully inclusive and accessible recruitment process. For further information on the accessibility support we can offer, please click here.We’re a big business and we can offer a range of diverse full-time & part-time working patterns across our many business areas, which means that we can find something that works for you. We work in a more blended pattern - combining office and remote working. Our offices will continue to be where we connect, collaborate and innovate. If you are applying internally, please speak to the Hiring Manager about how this can work for you - Everyone is welcome at Tesco.* Email### Share this job* Email Tesco Careers 2025. All rights reserved.