Senior Data Scientist

Harnham; Greater London; On-site; GBP 65,000 - 90,000; Full time

Benefits offered by this job

Hybrid working

Flexible hours

Private healthcare

Job summary

Harnham is seeking a Data Scientist for its Decision Sciences team in London or hybrid London/remote. The role focuses on building ML models for retention, churn, and CLV, with cross‑functional collaboration with CRM and marketing.

You will evaluate pipelines, design experiments, and deliver actionable insights that drive customer outcomes. The ideal candidate has strong Python/SQL, solid statistical modelling skills, and experience in marketing or ecommerce data environments.

Qualifications

• Experience as a Data Scientist in marketing/ecommerce/customer domains.
• Advanced Python and SQL in modern data environments.
• Strong understanding of statistical modelling and causal inference.
• Experience deploying predictive ML models.
• Ability to communicate findings to non-technical audiences.

Responsibilities

• Build and develop ML models for retention, churn, and customer lifetime value.
• Evaluate and improve modelling pipelines for accuracy and commercial impact.
• Partner with CRM and marketing teams to translate model outputs into actionable retention strategies.
• Develop forecasting and marketing effectiveness models to support business planning and decision-making.
• Design, analyse, and interpret A/B tests and experimentation frameworks.
• Deliver insight through dashboards and clear stakeholder communication.

Skills

Commercial Data Science experience

Python & SQL

Statistical modelling

ML model deployment

Communication of results

CRM/Lifecycle marketing exposure

Job description

DATA SCIENTIST, DECISION SCIENCES

London OR Cossington (Hybrid)

THE COMPANY

A data-driven consumer business with a large and engaged customer base is seeking a Data Scientist to join their Decision Sciences team. They are investing heavily in advanced analytics and machine learning, with data playing a central role in strategic decision-making across the organisation. You'll work in a collaborative environment alongside analytics, marketing, and commercial stakeholders, delivering solutions that have a tangible impact on customer outcomes.

THE ROLE

• Build and develop machine learning models focused on customer retention, churn prediction, and customer lifetime value
• Evaluate and improve existing modelling pipelines to increase accuracy and commercial impact
• Partner with CRM and marketing teams to translate model outputs into actionable retention strategies
• Develop forecasting and marketing effectiveness models to support business planning and decision-making
• Design, analyse, and interpret A/B tests and experimentation frameworks
• Deliver insight through deep-dive analysis, dashboards, and clear communication to stakeholders

YOUR SKILLS & EXPERIENCE

• Strong commercial experience as a Data Scientist within marketing, ecommerce, customer, loyalty, or membership environments
• Advanced Python and SQL skills, with experience working in modern data environments
• Strong understanding of statistical modelling, experimentation, and causal inference
• Experience building and deploying predictive machine learning models
• Ability to communicate technical findings to non-technical audiences
• Experience working closely with CRM or lifecycle marketing teams is advantageous

WHAT THEY OFFER

• Competitive salary plus bonus
• Hybrid working and flexible hours
• Private healthcare and enhanced pension package
• Additional annual leave and wellbeing benefits
• Ongoing learning and development opportunities
• Clear career progression within a growing data team