Software Engineer

Location: Portsmouth with a hybrid working model.

Hours: Full time

Salary: from £35,000 but negotiable, depending on experience. The role comes with a competitive benefits package including pension (7% company contribution), 25 days holiday and life insurance.

The Role:

Sirius Digital is a trusted provider of expertise in Software Engineering, Data Science, and AI, supporting clients in the defence, nuclear, space, and energy sectors. We specialise in software modelling and simulation, as well as robotics and autonomous systems, delivering technical consultancy and innovative solutions.

We are seeking a Software Engineer who combines strong technical skills with problem-solving ability and effective communication. You will work independently or as part of small teams, helping Sirius Digital grow while advancing your own expertise. We offer a competitive benefits package and clear opportunities for rapid career progression.

Responsibilities will include:

• Deliver technical consultancy projects to a high standard
• Develop and implement software solutions across areas such as wargaming, simulation, autonomous systems, digital twins, and synthetic environments
• Build and sustain strong client relationships
• Apply mathematical and computational techniques to solve real-world problems, developing innovative approaches as needed

About You

The successful candidate must be able to demonstrate the following essential and desirable skills and attributes.

• Experience designing and delivering performant software applications, ideally within a technical consultancy environment
• Knowledge of software modelling and simulation techniques
• Ability to analyse requirements and define technical specifications
• Experience in one or more of the following: videogame engine technology (e.g., Unreal Engine, Godot), entity or event-based simulation, robotics, and autonomous systems
• Proficiency in C/C++ or C# and Python
• Willingness to learn new technologies and programming languages
• Ability to apply mathematical or statistical methods to scientific or applied challenges
• Confidence working with large codebases and understanding hardware/performance constraints
• Strong interpersonal skills for client and stakeholder engagement
• Experience preparing technical reports and presenting to customers
• Willingness to travel within the UK and work on client sites as required
• Background working with Defence Digital, DE&S, Dstl, Frontline Commands, or the UK Defence industry
• Degree in a STEM or computing discipline, or equivalent experience
• Proficiency with MS Office (Excel, PowerPoint, Word)

What we offer

We offer a combination of mentoring and internal and external training opportunities, with specialist sector organisations and in-house courses. You will have exposure to subject matter experts and additional online learning packages.

The role comes with a competitive benefits package including:

• pension (7% company contribution)
• electric vehicle scheme

Other Requirements

• Candidates must have an existing right to live and work in the UK.
• Candidates must be willing to undergo an internal baseline personnel security standard check prior to starting their employment with the company.
• Candidates must be willing and eligible to complete a United Kingdom Security Vetting (UKSV) security clearance application to the Security Check (SC) level upon starting their employment with the company. To gain SC Clearance you will normally need at least 5 years’ UK residency.
• Clearance check (SC level) or hold a current SC clearance upon starting their employment with the company. To gain SC clearance you will normally need at least 5 years’ UK residency.

To Apply

To apply please send a covering email and CV to .

CVs are reviewed upon submission and initial phone for face-to-face interviews are likely to begin within two weeks. Feedback will be given on all interview candidates regardless of success.

Interested in this role?

Send us your CV and a bit about yourself!