PRINCIPAL DATA SCIENTIST – HYBRID (London, 3 days a week) £100,000–£125,000 based on experience THE COMPANY Join a high-impact data science team at a global marketing and customer experience company. As a Principal Data Scientist, you’ll lead the development of end-to-end machine learning solutions that drive business transformation across household-name clients. This role is ideal for a hands-on technical leader with the ability to shape strategy, influence stakeholders, and still get stuck into code. You’ll partner closely with engineers, strategists, and creatives in a genuinely cross-functional setting. THE ROLE As a Principal Data Scientist, you will: Lead the design, implementation, and deployment of advanced ML solutions across the full stack — from data engineering and modelling to cloud deployment (AWS) Scope and steer high-impact projects from ideation to delivery, aligning technical strategy with business objectives Serve as a technical mentor to mid-level and junior data scientists Represent the data science function in client conversations and cross-functional planning Maintain a high bar for clean, testable code and scalable, maintainable solutions Foster a culture of experimentation, velocity, and clear communication YOUR SKILLS AND EXPERIENCE Must-Have: 5 years of experience building and deploying DS/ML products in production Strong Python and SQL skills; deep understanding of ML lifecycle from prototyping to production Hands-on experience with AWS (or similar), Git, and CI/CD pipelines Strong track record leading technical delivery and collaborating with non-technical stakeholders Ability to balance high-level strategic thinking with hands-on implementation Excellent communicator, able to tailor messages for technical, creative, and client audiences Nice-to-Have: Experience with marketing data, customer-level modelling, or decision science (e.g. uplift, attribution, causal AI, optimization) Familiarity with MLOps tooling (MLflow, FastAPI, Airflow, etc.) Experience designing and interpreting A/B tests or other experimental frameworks Background in consulting, agency, or fast-paced environments where autonomy and adaptability are key WHY THIS ROLE IS DIFFERENT This is a senior role with real breadth — not just a leadership position in name. You’ll be hands-on where it counts, shaping projects, mentoring talent, and collaborating across disciplines to create meaningful, measurable impact. Ideal for someone ready to step into a technical leadership role while staying close to the work. HOW TO APPLY Interested? Apply via the link on this page with your CV.