Principal Software Engineer; C++​/Unreal Engine

Principal Software Engineer

Portsmouth | Hybrid, 3 days onsite

£75,000–£85,000 plus bonus and benefits

This Principal Software Engineer role is designed for a hands‑on technical leader with strong C++ and Unreal Engine expertise, working at the forefront of complex, performance‑critical software delivery. The role combines advanced engineering with genuine technical authority, shaping how simulation‑driven and autonomy‑focused systems are designed, built and evolved.

The position sits within a fast‑growing software and data science consultancy delivering end‑to‑end solutions across defence, energy, transport and health. You will work closely with subject matter experts and senior stakeholders on high‑impact programmes spanning modelling and simulation, autonomy, geospatial systems, synthetic environments and digital twins.

This is a true principal‑level role. You will remain deeply technical while setting direction, leading teams and acting as the technical authority across projects.

• Leading the design and delivery of complex software solutions using C++ and Unreal Engine
• Acting as technical lead across modelling and simulation, wargaming and autonomous systems
• Applying mathematical and computational techniques to solve real‑world problems
• Owning key technical decisions across architecture, tooling and performance
• Mentoring engineers and enabling high‑performing delivery teams
• Delivering technical consultancy engagements and leading selected projects
• Building trusted relationships with customers and stakeholders
• Supporting bids, proposals and technical reporting

• Extensive experience, typically 15+ years, delivering high‑performance software
• Proven technical leadership at Principal or Technical Lead level
• Strong hands‑on expertise in C++ and Unreal Engine
• Background in simulation, autonomy, robotics or game‑engine‑driven environments
• Experience working with large, complex codebases and performance constraints
• Strong stakeholder management, communication and influencing skills

• Salary up to £85,000, flexible for exceptional technical leaders
• 7 percent employer pension contribution
• Vitality private healthcare
• 25 days holiday with the option to buy or sell additional days
• Life assurance
• EV salary sacrifice scheme
• Discretionary bonus linked to company performance
• Structured mentoring and ongoing technical development