Gregory-Martin International
Principal Software Engineer
Job Description
Salary: £60,000 - 80,000 per year
Requirements:- At least 15 years experience in designing and implementing performant software applications.
- Ability to apply mathematical principles or statistical approaches to solve problems in scientific or applied fields.
- Proficiency in C/C++ or C# and Python.
- Strong stakeholder management skills, including influencing, negotiating, and conflict management.
- Experience writing proposals and coordinating bid management activity.
- Experience in line management and enabling people to perform.
- Extensive experience with a range of software modelling and simulation techniques.
- Experience using cases and project data context to determine specifications and requirements.
- Experience in one or more of the following technical disciplines: videogame engine technology such as Unreal Engine or Godot; entity or event-based simulation; robotics and autonomous systems.
- Ability to understand varied codebases and confidently make changes to large projects.
- Understanding of performance and hardware constraints.
- Experience building customer and stakeholder relationships.
- Experience supporting and leading the authoring of technical reports and presenting to customers.
- Willingness to travel across the UK and work at client sites for periods.
- Educated to degree level or have equivalent relevant experience.
- Strong STEM or computing background.
- Proficiency in MS Office, especially Excel, PowerPoint, and Word.
- Existing right to live and work in the UK.
- Current SC or DV Security Clearance is preferred.
- Design, develop, and deliver software solutions using a wide range of techniques, including wargames, modelling and simulation, robotic and autonomous systems, digital twins, and synthetic environments.
- Apply mathematical and computational methods to tackle real-world problems, using tools and techniques and developing novel approaches where required.
- Deliver technical consulting projects and products, with the opportunity to lead some of them.
- Build new customer relationships and maintain existing ones.
- Develop code in the software modelling and simulation, autonomy, and geospatial fields.
- Provide key advice on innovation and new techniques to stakeholders.
- Design solutions for complex challenges that meet and exceed user requirements.
- C#
- Excel
- Hardware
- Python
- Robotics
- Security
- Unreal
- GameDev
- C++
More:
We are a growing software and data science consultancy dedicated to delivering high-quality, end-to-end software and data science services. This Principal Software Engineer role is based in Portsmouth with a hybrid working pattern of three days in the office. We offer a salary from £60K to £80K depending on experience, along with many benefits including pension, 25 days holiday, and life insurance. The role gives you the opportunity to work across multiple sectors, including defence, energy, transport, and health, and contribute to cutting-edge solutions.
last updated 31 week of 2026
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About Gregory-Martin International
Gregory-Martin International
Portsmouth
IT
Skills & Technologies
Inferred from job description
Salary Insight
£70,000
This role
£60,000
UK median
This salary is 17% above the UK median for Software Engineers (£60,000/yr).
Based on 2024–2025 UK technology sector benchmarks