Software Developer- Application Development (Defence)
- Level
- Mid
- Visa
- Not offered
Not stated in the posting: salary, work type.
Open. First seen 3 October 2026.
About the role
- 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
Neptune North's standard text
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 Software Engineers to build the applications our defence clients rely on, across the full stack from database to browser. This is a hands-on engineering role where you will have impact across a wide variety of projects.
Potential projects might include fully engineered solutions, developing Proof of Concepts (POCs), and applied work to modernise or replace systems that our clients depend on every day.
Responsibilities
- Design, build and maintain web applications end to end, from data model through API to user interface
- Deploy and configure applications in cloud and on-premise environments
- Provide technical expertise when it is required within the organisation and in client engagements
- Demonstrate flexibility in taking on work aligned to evolving company priorities
- Play an active role in sharing expertise to raise and re-use capability
What makes a great candidate
- Excellent programming skills in one or more modern languages suited to backend development, 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 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 grounding in software engineering best practices and a desire to maintain high engineering standards in all your work
- Excellent verbal and written communication skills
- Experience working effectively as part of a team and enthusiasm for knowledge-sharing and collaboration
- Ability to work effectively with ambiguity, while maintaining a disciplined, outcome-focussed approach
- 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
- Experience in defence or national security is a strong plus
What you can achieve
- Contribute to software that strengthens UK defence and national security
- Build a strong foundation in production application engineering and best practices that will shape your career
- Develop your skills across the full stack and a variety of technologies
- Learn from experienced software engineers who are invested in your growth
- Contribute to meaningful technical decisions as part of a collaborative, low-ego engineering team
Neptune North's standard text
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.
Neptune North's standard text
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.
What this role asks for
Particular to this role
REST · React · TypeScript · WebSockets
Rare in Neptune North's other 18 open postings.
In most of Neptune North's ads
Python
Named in most of its open postings, whatever the role.
76% of this description is written for the role. The rest is Neptune North's standard text, folded away below.
Read against Neptune North's other open postings on this site.
The team: Defence HIRES STEADILY
This role is one of 10 open in Defence. 3 were posted in the last 30 days and the oldest in August: a team that hires all year rather than one being built.
WHAT THE TEAM WORKS WITH, ACROSS ITS POSTINGS
Python (8 of 10), Machine Learning (6 of 10), AWS (4 of 10), Azure (4 of 10), SQL (4 of 10), .NET (2 of 10), Airflow (2 of 10)
OTHER ROLES ON THIS TEAM
- Senior Machine Learning Engineer (Defence) posted Oct 14
- Machine Learning Engineer (Defence) posted Oct 14
- Senior Applied AI Engineer (Defence) posted Oct 14
- Senior Data Engineer (Defence) posted Aug 13
- Senior Software Developer- Low-Level and Embedded (Defence) posted Aug 13
- Senior Software Developer- Application Development (Defence) posted Aug 13
- Software Developer- Low-Level and Embedded (Defence) posted Aug 13
- Data Engineer (Defence) posted Aug 13
- Applied AI Engineer (Defence) posted Aug 10
From the team and dates on Neptune North's own job board.
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