Data Scientist

Kantar Media; City Of London; Hybrid; GBP 50,000 - 80,000; Full time

Job summary

A leading media analytics company in London seeks a Data Scientist to develop machine learning models, clean large datasets, and lead data science projects. The ideal candidate will have a strong Python background, experience in statistics, and effective collaboration skills. This is a full-time permanent position allowing hybrid work, requiring at least two days in the office weekly.

Benefits

Market competitive salary

Flexibility in work arrangements

Commitment to inclusion and diversity

Qualifications

• Experience using core data science libraries like pandas and NumPy.
• Practical application of statistics and machine learning.
• Ability to wrangle and explore data independently.

Responsibilities

• Develop and optimize machine learning models.
• Investigate and clean large datasets for quality.
• Lead data science projects from planning to execution.

Skills

Advanced programming in Python

Applied mathematics background

Statistical analysis experience

Work with large datasets

Model building and deployment

Familiarity with GPU-powered model development

Project management

Verbal and written communication

Collaborative skills

Education

Master's or PhD in a quantitative field

Tools

Databricks

Azure DevOps

Python libraries (pandas, NumPy, etc.)

Job description

Job Title: Data Scientist

Location: London

Work pattern: Full time/Permanent/Hybrid working. This is a full-time permanent position, based in our London office. We operate on a hybrid working arrangement and require a minimum of 2 days in the office. We welcome all applications from those with the legal right to live and work permanently in the UK, without requiring VISA sponsorship now or in the future.

Media help partners understand the changing advertising landscape. Specialising in audience measurement, consumer targeting and in-depth intelligence into paid, owned and earned media, their global coverage and local expertise enable better understanding of media audiences and their relationships with brands.

Kantar Media is a wholly owned but operationally independent part of the Kantar Group.

As people increasingly move across channels and platforms, Kantar Media's data and audience measurement, targeting, analytics and advertising intelligence services unlock insights to inform powerful decision‑making.

Working with panel and first‑party data in over 80 countries, we have the world's fastest growing cross‑media measurement footprint, underpinned by versatility, scale, technology and expertise, to drive long‑term business growth for our clients and partners.

Key Responsibilities

• Develop and enhance statistical, mathematical, and machine learning models, including prototyping and optimizing for production use.


• Investigate and clean large datasets, identifying errors, inconsistencies, and anomalies to ensure data quality for modelling.


• Lead and manage data science projects independently, including planning, execution, and reporting.


• Collaborate with internal teams, clients, and stakeholders to gather requirements, align on goals, and design appropriate data science solutions.


• Design and contribute to robust, scalable libraries and repositories, supporting internal modelling tools and workflows.


• Assist in transitioning systems to cloud‑based platforms, especially using Databricks and Azure.


• Generate internal and external reports and support proposal writing and project design.


• Explore and apply LLMs and emerging AI techniques to media and audience measurement challenges.


• Participate in code reviews, design sessions, and documentation to uphold best practices and maintain code quality.


• Ensure smooth integration of models into production, working closely with cross‑functional teams to align with product and operational requirements.

Skills & Experience

• Advanced programming in Python, with experience using core data science libraries (e.g., pandas, NumPy, SciPy, scikit‑learn).


• Strong background in applied mathematics, statistics, or machine learning, with practical application to real‑world problems.


• Experience in statistical analysis, machine learning, segmentation, and statistical matching techniques.


• Ability to work with large, complex datasets, including data wrangling and exploratory data analysis.


• Experience building and deploying models, ideally in production environments.


• Familiarity or interest in GPU‑powered model development, using frameworks like PyTorch, TensorFlow, or JAX.


• Proven ability to work independently, take initiative, and manage end‑to‑end data science projects.


• Strong verbal and written communication skills, with the ability to explain technical concepts clearly.


• Effective collaboration skills, including openness to feedback and team interaction.


• Master's or PhD in a quantitative field (e.g., mathematics, statistics, computer science), or equivalent real‑world experience.


• Bonus: experience in at least one of the following areas:
  
  
  • Working with Marketing Mix Models (MMMs)
  
  
  • Practical applications of Large Language Models (LLMs) or NLP
  
  
  • Understanding of web technologies and identifiers (e.g. cookies, device IDs, MAIDs, etc.)
  
  


• Familiar with repository‑based version controls (e.g., git/Azure DevOps)


• Experience with Azure Databricks platform

Our offer

At Kantar we have an integrated way of rewarding our people based around a simple, clear, and consistent set of principles. Our approach helps to ensure we are market competitive and to support a pay for performance culture, where your reward and career progression opportunities are linked to what you deliver. We go beyond the obvious, using intelligence, passion, and creativity to inspire new thinking and shape the world we live in. Apply for a career that's out of the ordinary and join us. We want to create an equality of opportunity in a fair and supportive working environment where people feel included, accepted, and are allowed to flourish in a space where their mental health and wellbeing is taken into consideration. We want to create a more diverse community to expand our talent pool, be locally representative, drive diversity of thinking and better commercial outcomes. At Kantar, the diversity of our employees provides a richer environment for our employees and broader depth and breadth of thinking for our clients. Kantar is committed to inclusion and diversity; therefore, we welcome applications from all sections of society and do not discriminate because of age, race, religion, gender, pregnancy, sexual orientation, gender identity, disability, marital status, or any other legally protected characteristics.

Privacy and Legal Statement: Please note that by applying to this opportunity you consent to the personal data you provide to us to be processed and retained by The Kantar Group Limited ('Kantar'). Your details will be kept on our Internal ATS for as long as is necessary for the purposes of recruitment, which may include your details being shared with the hiring manager(s) and for consideration for potential future opportunities by Kantar and its affiliate Kantar group companies. For full details of our privacy policy please visit www.kantar.com

Country: United Kingdom

Why join Kantar? We pride ourselves on understanding people, and what makes us think and act the way we do. And because we know people, we like to make sure our own people are being looked after as well. Equality of opportunity for everyone is our highest priority and we support our colleagues to work in a way that supports their health and wellbeing. While we encourage teams to spend part of their working week in the office, we understand no one size fits all; our approach is flexible to ensure everybody feels included, accepted, and that we can win together. We're dedicated to creating an inclusive culture and value the diversity of our people, clients, suppliers and communities, and we encourage applications from all backgrounds and sections of society. Even if you feel like you're not an exact match, we'd love to receive your application and talk to you about this job or others at Kantar.