Principal Software Engineer

Job Description:

Your impact 

Are you ready to take on complex software challenges and provide technical authority across programmes? At Leonardo, our Principal Software Engineers are recognised subject matter experts, shaping architectures, driving innovation, and ensuring that our solutions remain secure, robust, and future-ready.

Your work at Leonardo UK will see you take the lead in solving customer problems in an agile, innovative and team-centric manner. The role may involve a blended hybrid working model, with a mixture of working from home and working on site at one of our Leonardo offices to ensure close collaboration with the wider team and with our customers.

What you will do as a Principal Software Engineer

• Act as a technical authority on software design, coding standards, and integration.

• Lead the design and development of complex software components and frameworks.

• Provide expert guidance on secure coding, software assurance, and compliance requirements.

• Mentor and coach engineers at all levels, raising the technical capability of the team.

• Drive innovation through adoption of modern languages, frameworks, and tooling.

• Contribute to architectural decisions and system-level designs.

• Review designs, code, and test evidence to ensure quality and robustness.

• Engage with customers and stakeholders to explain, defend, and optimise technical solutions.

What you’ll bring

• Extensive technical expertise in software development, frameworks, and architectures.

• Ability to act as a technical authority while remaining hands-on.

• Strong communication skills with the ability to engage with both engineers and customers.

Core areas (must have): 

• Expert-level proficiency in one or more programming languages (e.g. Python, Java, C++, C#)

• Experience designing and implementing complex software solutions

• Strong knowledge of secure coding practices and cyber security considerations

• Familiarity with modern software development practices (CI/CD, DevSecOps, Agile/SAFe)

• Experience integrating software within complex systems and platforms

• Ability to influence technical direction and mentor engineers

Desirable: 

• Industry certifications or professional recognition (e.g. Chartered Engineer, AWS/Azure Architect, CISSP)

• Experience with cloud-native development and containerised platforms (Docker, Kubernetes, OpenShift)

• Knowledge of software modelling and design approaches (UML, SysML, model-based engineering)

• Exposure to AI/ML development practices or data engineering

• Experience contributing to technical standards or professional communities

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: https://careers.uk.leonardo.com/gb/en/security-and-vetting

Location 

This role can be based at one of our UK sites, Bristol, with hybrid/custom working options where appropriate.

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 mental health support, financial advice, and employee-led networks championing inclusion and diversity (Enable, Pride, Equalise, Armed Forces, Carers, Wellbeing and Ethnicity).

• Rewarding Performance: All employees at management level and below are eligible for our bonus scheme.

• Never Stop Learning: Free access to 4,000+ online courses via Coursera and LinkedIn Learning.

• Refer a friend: Receive a financial reward through our referral programme.

• Tailored Perks: Spend up to £500 annually on flexible benefits including private healthcare, dental, family cover, tech & lifestyle discounts, gym memberships and more.

• Flexible working: Flexible hours with hybrid working options. For part time opportunities, please talk to us about what might be possible for this role.

For a full list of our company benefits please visit our website.

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.
Leonardo is a global leader in Aerospace, Defence, and Security. Headquartered in Italy, we employ over 53,000 people worldwide including 8,500 across 9 sites in the UK. Our employees are not just part of a team—they are key contributors to shaping innovation, advancing technology, and enhancing global safety.

At Leonardo we are committed to building an inclusive, accessible, and welcoming workplace. We believe that a diverse workforce sparks creativity, drives innovation, and leads to better outcomes for our people and our customers. If you have any accessibility requirements to support you during the recruitment process, just let us know.

Be part of something bigger - apply now!

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Primary Location:

GB - Bristol - Coldharbour Lane

Contract Type:

Permanent

Hybrid Working:

Hybrid