Senior Software Developer- Application Development (Defence)

• Location: Newcastle upon Tyne
• Security clearance: must be eligible for UK SC-level security clearance (UK national)
• Visa sponsorship: we are not able to sponsor visas for this role
• Closing date: applications reviewed on a rolling basis

About Neptune North

Neptune North is a high-performing technical consultancy. We build data, AI and software solutions for clients in defence, financial services and private capital, working on demanding problems in challenging environments.

We were founded in 2024 as a joint venture between Oliver Wyman and Rokos Capital Management. We’re headquartered in the centre of Newcastle upon Tyne, with a growing international footprint, and we’re recruiting exceptional engineers across every level.

The role

We’re looking for a Senior Software Engineer to lead application development on demanding defence projects and to help provide technical oversight to a new and rapidly growing team. You will help define and strengthen the application engineering capabilities that differentiate Neptune North and build a trusted reputation across defence clients.

Responsibilities also include contributing to business development, providing technical expertise and mentoring, overseeing the quality of deliverables, and hands-on involvement in projects.

This is a technical leadership role for an engineer who wants to stay close to the code. Potential projects span fully engineered solutions, developing Proof of Concepts (POCs), and modernising systems our clients depend on every day.

Responsibilities

• Influence the technical direction and play a key role in strengthening Neptune North’s application engineering capabilities
• Provide leadership and hands-on delivery in a wide range of software projects
• Set and maintain technical direction, architecture and standards, and make pragmatic trade-offs between speed, quality and long-term maintainability
• Run code and design reviews, set the bar for quality, and hold the team to it
• Work directly with clients to shape requirements, manage expectations, and to build trust
• Contribute to winning work by helping to write compelling bids and high-quality technical proposals
• Demonstrate flexibility in taking on work aligned to evolving company priorities
• Advocate knowledge sharing across the team and identify opportunities for reuse of capabilities
• Regularly provide career and technical mentorship to other engineers to build a high calibre engineering team

What makes a great candidate

• Minimum 5 years employment experience delivering and/or overseeing production web applications
• Excellent programming skills in one or more modern backend languages, such as C#/.NET, Java or Python
• Experience of web application development, including SQL databases, web frameworks and RESTful API design
• Frontend development in React and TypeScript, with experience using WebSockets, SignalR or similar real-time transport technologies
• Experience of modern end-to-end software engineering workflows, including requirements management, design, development, testing, deployment and maintenance
• Experience of cloud deployment and configuration, ideally on Azure or AWS
• Experience integrating AI-assisted tools into development workflows without compromising on quality, security or compliance
• A solid understanding of software engineering processes, and a drive to embed best practices in teams
• Excellent verbal and written communication skills and the ability to adapt communication according to the audience
• Experience working effectively in a team and a commitment to knowledge-sharing and collaboration
• Strong academic foundations, typically a first-class or 2:1 degree from a leading university in Computer Science, Engineering, Physics or Mathematics, or a related discipline
• Ability to work effectively with ambiguity, while maintaining a disciplined, outcome-focussed approach
• Experience in defence or national security is a strong plus
• Experience writing technical proposals or bids is a plus

What you can achieve

• Shape software that strengthens UK defence and national security
• Play a critical role in building and nurturing a rapidly expanding world-class engineering team
• Gain broad experience across interesting software projects applied to challenging environments
• Be part of a collaborative, low-ego team

Why join us

• Work on a wide variety of interesting problems alongside high-calibre colleagues. Our culture is collaborative and supportive. Neptune North is a place where people help each other grow and feel a real sense of belonging
• 25 days’ holiday allowance plus bank holidays
• Matching pension contributions up to 6%
• Private health insurance through Bupa
• Discretionary bonus

Travel

Neptune North works with clients across the UK’s defence sector. Many engagements involve regular travel and time on client site. This could mean two to three days per week over an entire assignment, or shorter periods of full-time on-site working anywhere in the UK, at sites including Cheltenham, Bristol, Glasgow, Portsmouth or other defence hubs. We support travelling staff with full expenses and hotel arrangements, and we discuss client placements with you in advance. We are looking for engineers who see this variety as part of the appeal of consultancy work rather than a downside.

Interview process

Our interview process is rigorous because the standard internally is high. For this role, it has three stages:

• Written questions, which you complete at a time that suits you
• A first interview covering your CV, experience and career aspirations
• A technical interview with members of our engineering team

Equity, diversity and inclusion

At Neptune North we are committed to a work environment that embraces diversity, equity and inclusion. We believe diverse backgrounds, perspectives and experiences help us attract, develop and retain the best talent. We do not discriminate on the basis of gender, age, race or ethnicity, identification as an LGBTQIA+ individual, religion, disability, or any other characteristic protected by relevant local law.