Lead Data Scientist - Defence Sector (Weekly Client Onsites)

Harnham; Greater London; On-site; GBP 80,000 - 120,000; Full time

Job summary

Harnham is building a dedicated AI & Data Science capability in Defence and is seeking senior data science leaders to deliver ML, GenAI and simulation solutions on-site across UK client locations.

You will own technical delivery and stakeholder engagement in a high-trust, autonomous consulting environment, with progression opportunities and exposure to mission-critical outcomes.

Qualifications

• Lead level experience 3-5 years, Principal level 5-10+ years in data science/ML.
• British citizenship or Security Clearance eligibility required.
• On-site work across UK client locations with travel and accommodation expensed.
• Ability to translate analytics into measurable business outcomes.

Responsibilities

• Build and deploy ML models and simulation tooling in secure environments.
• Lead technical delivery across multi-disciplinary teams including consultants and engineers.
• Work with client stakeholders on-site to co-design and iterate solutions.
• Translate complex analytics into strategic business outcomes with measurable value.

Skills

ML modelling

Stakeholder engagement

Client delivery

On-site delivery

Job description

Are you ready to apply data science where it matters most?

Do you want your models to drive real-world outcomes in mission-critical settings?

Do you enjoy working onsite with a variety of invested clients?

A leading UK consultancy is building a dedicated AI & Data Science team to strengthen its delivery capability in Defence. They're known for outcome-driven transformation work and operate a genuinely hands-on model where technical teams embed with client stakeholders to make change stick. The business has a strong track record across complex, high-stakes environments, and is now scaling its DS capability to deliver ML, GenAI and simulation solutions end-to-end. For high performers, there's clear progression and the chance to shape the direction of a growing AI practice.

You’ll work directly with end users and senior stakeholders to shape solutions from concept through to embedded impact. This is a high-trust, high-autonomy role where you’ll own both technical delivery and stakeholder engagement - all within a deeply collaborative consulting environment.

They're hiring at Lead (3-5 years of experience) to Principal level (5-10+ years of experience).

Key Responsibilities

• Build and deploy machine learning models and simulation tooling in secure environments
• Lead technical delivery across multi-disciplinary teams, including consultants and engineers
• Work closely with client stakeholders on-site to co-design and iterate on solutions
• Translate complex analytics into strategic business outcomes with measurable value

Working model: On-site 4-5 days/week across UK client locations (travel and accommodation expensed)

Clearance: British citizenship / Security Clearance eligibility required