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.

What you will be doing
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

What you will bring
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

What's on offer
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