Data Scientist (Mid-level) in City of Westminster

We are looking for a mid-level Data Scientist to help us develop, improve and deploy the models, tools and analytical methods that sit at the heart of our work. This role will focus on polling, economic, demographic and political data, including our proprietary modelling approaches. You will work across client projects, internal product development and new AI-enabled capabilities, helping us turn complex data into clear, reliable insight. The scope of the role will evolve as we integrate new tools and capabilities into the business. We are looking for someone who is technically strong, adaptable, curious and comfortable working across modelling, analysis, automation and product development. AI tools are now a central part of how the team builds. You will be expected to use them confidently, for code, for data work, for documentation, and to help us decide which workflows to automate next. The scope of the role will change as we integrate and roll out new AI capabilities; comfort with that shifting picture matters more than mastery of any single tool today.

What you will be responsible for:

• You will help build, test and improve statistical and machine-learning models using polling, demographic, economic and behavioural data.
• You will work with senior colleagues to design modelling approaches that answer real-world political, policy and commercial questions.
• You will support the development of proprietary models, including models of public opinion in Britain and other countries.
• You will help translate complex model outputs into clear findings for consultants, clients and non-technical audiences.
• You will contribute to internal tools and workflows that make our analysis faster, more reliable and easier to use.
• You will use Python, SQL, modern data libraries and AI-enabled tools to prototype, analyse and deliver work efficiently.
• You will work flexibly across projects, sometimes focused on modelling, sometimes on analysis, automation, data preparation or product development.
• You will help ensure our analytical work is robust, well-documented and delivered to a high standard.

What we are looking for from an ideal candidate:

• Around three years’ experience in a data science, statistical modelling, research science or similar role.
• Strong Python skills, including experience with modern data science libraries.
• Good SQL skills and confidence working with structured datasets.
• Experience building statistical, predictive or machine-learning models.
• Strong understanding of data quality, model validation and uncertainty.
• Interest in public opinion, politics, policy, economics or social research.
• Ability to work with messy real-world data and turn it into structured, useful analysis.
• Confidence using AI tools to speed up research, coding, analysis or workflow development.
• Experience with polling, survey data, demographic modelling or MRP would be a strong advantage, but is not essential.

Person Profile:

We are looking for someone who is curious, adaptable and motivated by the opportunity to use data and technology to solve real-world problems. You should be excited by the current pace of change in AI and data, and interested in helping us apply new capabilities in practical, valuable ways. You do not need to know every tool already, but you should be comfortable learning quickly, experimenting carefully and applying new techniques to live work. You should enjoy working on a mix of projects, from client-facing analysis to internal tools, pipelines, models and automations. The right person will be comfortable with some ambiguity and will be able to move between technical detail and practical delivery. You should be a strong problem-solver, with the creativity to find better ways of doing things and the discipline to deliver reliable work under pressure. You should be able to explain complex technical ideas in simple, clear language to colleagues and clients who may not have a technical background. You should care about quality, accuracy and clarity, especially when working with data that informs strategic decisions. You should be collaborative, pragmatic and willing to support colleagues as new tools and workflows are adopted across the business. Above all, we are looking for someone who wants to help deliver change for clients and for the business: someone who can combine technical skill, judgement and curiosity to build better ways of working.

Salary and Benefits:

• Salaries are competitive and subject to experience - we're looking for the right candidate.
• 25 days annual holiday with additional office closure days.
• A discretionary annual bonus (potential of 15% of annual salary), based on personal and business performance.
• Enhanced company pension contribution of 5% of annual salary.
• Private healthcare cover, inclusive of dental and optical.
• An enhanced family leave package.
• Bike and Electric Vehicle salary sacrifice schemes.
• An employee assistance programme with 24/7 access to online, phone or face-to-face counselling.
• We are based in Central London, close to several public transport links and for anyone who prefers to cycle in we offer bike storage and showers on site.
• We encourage a mix of home and office-based working.

Application:

Please submit a cover letter and CV using the application form below by midnight on 05 June 2026. We typically have a two stage interview process and a technical test as part of one of the rounds. Stonehaven is proud to be an equal opportunity employer. We are committed to equal opportunity and equal pay regardless of background, including race, religion, sex, national origin, sexual orientation, disability or gender identity. If you require any reasonable adjustments to participate in this recruitment process, please get in touch. Please only apply if you have the right to work in the UK.