Principal Software Engineer; AI​/ML

Salary Range: £54,000 - £70,000. Leonardo UK operates a grade-based salary framework with broad bands. The salary range shown reflects the approved grade band for this role, or a narrower hiring range published within that band, and is benchmarked against the external market. Exceptions above the standard range are managed through governance controls to protect internal equity.

Are you a software engineer with a working knowledge of Artificial Intelligence (AI) and Machine Learning (ML)? If you are interested in developing software for cutting‑edge defence and aerospace projects such as a sixth‑generation stealth fighter jet or a revolutionary Laser Directed Energy product, Leonardo would like to hear from you. We are seeking Senior or Principal Software Engineers with an interest in AI/ML to join our Electronics UK business.

Successful candidates will contribute to the delivery of leading‑edge solutions for challenging civilian and military projects.

Support our systems engineers on research projects while developing deployable software solutions that leverage AI/ML capabilities.

• Experience of, and a passion for, AI/ML.
• A degree in Computer Science, Engineering, or a related technical discipline, combined with practical experience delivering high‑integrity software products within a regulated environment.
• Industry experience working on Agile projects across the full software life cycle.
• Proficiency in machine learning frameworks such as PyTorch and Tensor Flow, as well as tools for model integration.
• Strong foundation in AI/ML, including transformer architectures, tokenisation, embeddings, and fine‑tuning large language models (LLMs).
• Experience building scalable pipelines, including APIs, vector databases, retrieval‑augmented generation (RAG), and orchestration frameworks.
• Experience curating datasets, managing embeddings, and ensuring security, privacy, and responsible AI practices.
• Experience in prompt engineering, with the ability to design, test, and systematically improve prompts, while measuring the accuracy, bias, and robustness of LLM outputs.
• Awareness of agentic workflows involving AI agents that can plan, reason, and take autonomous actions.
• Awareness of governance, security, and compliance considerations relating to data management and AI deployment.
• Awareness of mathematical libraries used for signal, image, and data processing.
• Awareness of high‑performance computing and the challenges associated with parallel processing.
• Willingness to learn and develop, even if not all requirements are met.

This role is subject to pre‑employment screening in line with the UK Government’s Baseline Personnel Security Standard (BPSS). Additional Personnel Security Controls may apply, including National Security Vetting (NSV) such as The Security Check (SC) or Developed Vetting (DV). For more information and guidance please visit:

• Enjoy generous leave with the opportunity to accrue up to 12 additional flexi‑days each year.
• Benefit from our award‑winning pension scheme with up to 15% employer contribution.
• Free access to mental health support, financial advice, and employee‑led networks championing inclusion and diversity (Enable, Pride, Equalise, Armed Forces, Carers, Wellbeing and Ethnicity).
• All employees at management level and below are eligible for our bonus scheme.
• Free access to 4,000+ online courses via Coursera and Linked In Learning.
• Receive a financial reward through our referral programme.
• Spend up to £500 annually on flexible benefits including private healthcare, dental, family cover, tech & lifestyle discounts, gym memberships and more.
• Flexible hours with hybrid working options. For part‑time opportunities, please talk to us about what might be possible for this role.

Primary: GB
- Luton
- Cap. Green 300

Additional: GB
- Basildon, GB
- Edinburgh, GB
- Lincoln, GB
- Newcastle, GB
- Southampton

Permanent. Hybrid Working:
Hybrid International, multicultural, innovative, technological.