Lead Data Scientist

IO Associates; Fleckney; Hybrid; GBP 60,000 - 75,000; Full time

Job summary

A leading eCommerce business in the UK is looking for a Lead Data Scientist to take ownership of its core algorithms. This technical leadership role involves designing and deploying advanced predictive models and leading the algorithm roadmap for a new internal ads platform. Ideal candidates should have a strong background in data science, proven experience in machine learning systems, and expertise in tools like PyTorch or TensorFlow. The position offers competitive salary with bonuses, generous benefits, and a flexible working environment.

Benefits

Annual performance bonus

Sharesave scheme

Private medical insurance

Pension contribution

25 days holiday plus bank holidays

Staff discounts

Subsidised food

Gym discounts

Digital GP service

Qualifications

• Strong background in data science applied to personalisation, recommendations, or ranking problems.
• Proven experience owning and delivering production machine learning systems.
• Strong Python and SQL skills with experience in distributed processing such as PySpark.

Responsibilities

• Own the technical and algorithm roadmap for a large-scale internal ads platform.
• Design, test and deploy advanced predictive and ranking models.
• Lead architecture, model selection, and production design decisions.

Skills

Data science applied to personalisation

Production machine learning systems

PyTorch

TensorFlow

Python

SQL

Distributed processing (PySpark)

Tools

MLflow

Databricks

Job description

Lead Data Scientist

Location: Midlands based HQ with weekly on-site presence
Salary: Up to £75,000 plus competitive bonus and benefits

A large UK consumer eCommerce business is scaling a new internal advertising and monetisation platform and is hiring a Lead Data Scientist to take technical ownership of its core algorithms. This is a technical leadership role with end-to-end ownership of the algorithm roadmap. You will set direction, make architectural decisions, and lead delivery from experimentation through to production in a high-scale environment.

What you will do

• Own the technical and algorithm roadmap for a large-scale internal ads platform.
• Design, test and deploy advanced predictive and ranking models such as Two-Tower architectures, RNNs and learning-to-rank approaches.
• Lead architecture, model selection and production design decisions.
• Improve feedback loops to increase responsiveness to real-world events and outcomes.
• Set best practices for production ML, testing, monitoring and deployment.
• Act as the technical authority for data science across the ads domain.
• Work closely with engineering, product and commercial teams.
• Present outcomes and recommendations to senior stakeholders in clear business terms.

What you bring

• Strong background in data science applied to personalisation, recommendations or ranking problems.
• Proven experience owning and delivering production machine learning systems.
• Advanced hands‑on experience with PyTorch or TensorFlow.
• Strong Python and SQL skills with experience in distributed processing such as PySpark.
• Comfortable making technical trade-offs in complex, ambiguous environments.
• Able to translate complex technical work into commercial impact.

Nice to have

• Experience in AdTech or monetisation systems.
• Familiarity with MLflow, Databricks and modern DevOps tooling.
• Experience working in large-scale consumer or eCommerce environments.

Working style and benefits

• Weekly on-site presence with flexible working.
• Competitive base salary with annual performance bonus.
• Sharesave scheme.
• Private medical insurance.
• Pension contribution.
• 25 days holiday plus bank holidays with buy and sell options.
• Staff discounts.
• Subsidised food and on-site facilities.
• Gym discounts.
• Digital GP service and wellbeing support.

Why join

You will be joining a business operating at national and international scale, investing heavily in applied machine learning that directly impacts revenue. This is not a research role. Your work will be put into production, used at scale, and you will be accountable for its impact.