Software Developer- Application Development (Defence)

Neptune North; Newcastle upon Tyne; On-site; GBP 65,000 - 95,000; Full time

Benefits offered by this job

25 days holiday

Private health insurance (Bupa)

Discretionary bonus

Matching pension up to 6%

Job summary

Neptune North in Newcastle upon Tyne is seeking Software Engineers to build applications for defence clients, spanning the full stack from database to browser. This hands-on role offers impact across diverse projects, from fully engineered solutions to proofs of concept, with daily responsibilities in modernising or replacing critical systems.

You will work in a collaborative, high-performance team, applying best practices, and delivering secure, high-quality software.

Qualifications

• Proficient in backend languages like C#/.NET, Java or Python.
• Experience building web apps with SQL databases, web frameworks, and RESTful APIs.
• Frontend experience with React and TypeScript; real-time tech like WebSockets/SignalR.
• Cloud deployment experience, preferably Azure or AWS.

Responsibilities

• Design, build and maintain web apps end to end from data model to UI.
• Deploy and configure apps in cloud and on-prem environments.
• Provide technical expertise in the organisation and client engagements.
• Adapt to changing priorities and share expertise to raise capability.
• Collaborate to raise reusable engineering capability.

Skills

C#/.NET

Java

Python

React

TypeScript

REST APIs

WebSockets

Cloud (Azure/AWS)

AI in development

Teamwork

Education

CS/Engineering/Physics/Math degree

Tools

Azure

AWS

SQL

Job description

• 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 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-focused 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

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.