Principal Software Engineer; AI​/ML

hackajob is collaborating with Leonardo to connect them with exceptional professionals for this role.

Job Description:

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.

Your Impact

Are you a software engineer with a working knowledge of Artificial Intelligence (AI) and Machine Learning (ML)? Are you interested in developing software for some of the most cutting-edge defence and aerospace projects in the UK? If the prospect of developing software for projects such as a sixth-generation stealth fighter jet or a revolutionary Laser Directed Energy product excites you, then Leonardo would like to hear from you.

Leonardo is seeking to recruit Senior or Principal Software Engineers with an interest in Artificial Intelligence and Machine Learning to join our well-established software community within our Electronics UK business. Successful candidates will contribute to the delivery of leading-edge solutions for challenging civilian and military projects.

Leonardo has a significant interest in exploiting AI/ML technologies. In this role, you will support our systems engineers on research projects while developing deployable software solutions that leverage AI/ML capabilities.

What you'll bring

You will have experience of, and a passion for, AI/ML. You should hold a degree in Computer Science, Engineering, or a related technical discipline, combined with practical experience in delivering high-integrity software products within a regulated environment.

We are looking for candidates with the following technical skills:

• 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.
• A 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.

This list is not exhaustive, and we are keen to hear from you even if you do not meet every requirement. The most important attribute is a willingness to learn and develop.

Security Clearance

This role is subject to pre-employment screening in line with the UK Government's Baseline Personnel Security Standard (BPSS). An additional range of Personnel Security Controls referred to as National Security Vetting (NSV) may apply, this could include meeting the eligibility requirements for The Security Check (SC) or Developed Vetting (DV). For more information and guidance please visit:

Why join us

At Leonardo, our people are at the heart of everything we do. We offer a comprehensive, company-funded benefits package that supports your wellbeing, career development, and work-life balance. Whether you're looking to grow professionally, care for your health, or plan for the future, we're here to help you thrive.

• Time to Recharge: Enjoy generous leave with the opportunity to accrue up to 12 additional flexi-days each year.
• Secure your Future: Benefit from our award-winning pension scheme with up to 15% employer contribution.
• Your Wellbeing Matters: Free access to…