Applied ML Technical Lead, Defence

The role

You will lead the technical direction and day-to-day progress of applied machine learning projects for UK Defence and national security. You will design, build, and train models while working with Defence stakeholders to translate operational needs into technical capabilities.

What you will do

• Design, build, train and evaluate machine learning models for Defence use cases.
• Work on problems involving complex sensor data, signal processing, and multimodal intelligence.
• Develop and improve model architectures, training pipelines, and inference systems.
• Translate research prototypes into reliable, deployable capabilities.
• Own the technical direction and day-to-day progress of applied ML projects.
• Coordinate work across ML researchers, software engineers, and infrastructure teams.
• Engage with technical and operational stakeholders across the UK Defence ecosystem.
• Translate customer requirements into technical objectives and delivery plans.
• Deploy ML models into secure, on-premise and resource-constrained systems.
• Establish feedback loops between operational users and engineering teams.

Required qualifications

• Background in applied machine learning, ML engineering, research engineering or a similarly technical role.
• Experience taking ownership of complex technical work.
• Writing production-quality Python.
• Working with modern ML frameworks such as PyTorch.
• Building, training, fine-tuning and evaluating machine learning models.
• Working with complex datasets, designing experiments and interpreting model performance.
• Understanding trade-offs between model performance, compute requirements, latency and deployment constraints.
• Working with engineering infrastructure, including Git, containers, Linux and GPU compute.
• Taking technical ownership of projects with multiple stakeholders and evolving priorities.
• Communicating technical concepts clearly to researchers, engineers, senior stakeholders and operational users.
• Must be eligible to hold UK Security Vetting Clearance SC or above.

Nice to have

• Existing UK security clearance, such as SC or DV
• Previous experience working in secure Defence environments
• Experience with signal processing, time-series data, sensor fusion, representation learning or machine learning applied to complex real-world datasets
• Experience with foundation models, multimodal learning or advanced model training and post-training techniques
• Experience deploying ML models to edge devices or constrained compute environments
• Familiarity with UK Defence procurement, technical assurance or the national security landscape
• Experience leading technical workstreams or working as a technical lead on customer-facing ML projects

Benefits

• Competitive salary, benchmarked to the market
• Equity / share options
• 30 days holiday + bank holidays
• Dog-friendly office
• Weekly team breakfast & lunch
• Monthly socials
• Pension
• High-quality equipment

Before you apply

• Must be eligible to hold UK Security Vetting Clearance SC or above

About the company

Cosine is a UK AI lab building models, applications and training infrastructure for mission-critical organisations. They are training Lumen Sovereign, the first frontier large language model trained in the UK.