Staff Software Engineer

Addition; Greater London; Remote; GBP 110,000 - 170,000; Full time

Benefits offered by this job

Equity

Annual bonus

Remote work (predominantly)

Flexible location

Job summary

Addition is seeking a senior technical leader to shape architecture, lead delivery teams and translate complex Defence challenges into robust, production-grade systems. You’ll own the technical direction across software, data and AI projects, drive architectural decisions, mentor engineers and engage with senior stakeholders.

The role is predominantly remote with occasional travel to client sites in London when required.

Qualifications

• Degree in Computer Science, Engineering, Mathematics, Physics, Statistics, Data Science or another relevant technical discipline.
• Strong track record of leading complex software, data or AI projects through the full development lifecycle.
• Previous experience within Defence, national security or another highly technical and regulated environment.
• Strong Python engineering skills with experience building high-quality production software.
• Deep understanding of software architecture, backend engineering, APIs, databases and data pipelines.
• Hands-on experience with cloud environments such as AWS or Azure alongside Docker, Git and CI/CD.
• Practical experience designing and delivering machine learning and AI systems, including Large Language Model applications.
• Strong knowledge of software engineering principles, code quality and technical design reviews.
• Ability to quickly understand complex technical and domain-specific challenges and turn them into practical solutions.
• Confidence leading multidisciplinary technical teams and making high-impact engineering decisions.
• Strong client-facing skills with experience communicating technical concepts to senior stakeholders and subject matter experts.
• Ability to mentor engineers and data scientists while maintaining high technical standards.
• Strong analytical, organisational and project planning skills.
• Existing DV clearance, or eligibility and willingness to undergo DV clearance.

Responsibilities

• Own the technical direction and architecture of complex software, data and AI projects from initial discovery through to deployment.
• Lead engineering teams, set technical standards and make pragmatic architectural decisions that balance quality, performance and delivery.
• Design and build backend services, APIs, integrations and scalable data pipelines.
• Develop production-ready AI and machine learning solutions, including systems using Large Language Models.
• Review code and technical designs, ensuring engineering work remains maintainable, secure and fit for purpose.
• Apply modern engineering practices across Git, Docker, CI/CD and cloud-based deployments.
• Get up to speed quickly with unfamiliar scientific, engineering, operational and commercial problem spaces.
• Work closely with Defence specialists and subject matter experts to understand operational requirements and challenge assumptions where needed.
• Lead client workshops, technical discussions and project meetings with senior stakeholders.
• Translate complex operational and business requirements into clear, achievable technical strategies.
• Remove technical blockers and provide hands‑on guidance to engineers and data scientists throughout delivery.
• Support technical discovery, project scoping, bids and commercial proposals.
• Help develop reusable engineering approaches, standards and best practices across the wider technical team.
• Mentor colleagues and contribute to a culture of continuous technical development.

Skills

Python

Software architecture

Cloud (AWS)

Cloud (Azure)

Docker

Git

CI/CD

Leadership

DV clearance

Client engagement

Data pipelines

Machine learning

Education

Degree in Computer Science or related

Tools

Docker

Git

CI/CD

Job description

We’re working with a specialist technology business delivering complex software, data and AI solutions across the Defence sector. This is a senior technical role where you’ll shape architecture, lead delivery teams and turn challenging real-world problems into robust, production-ready systems.

Role Overview:

• Location: Predominantly remote, with travel to client sites in London and surrounding areas around 2 days per week
• Package: Competitive salary + annual performance bonus + equity
• Industry: Defence & Security / Software Engineering / AI

What You’ll Be Doing:

• Own the technical direction and architecture of complex software, data and AI projects from initial discovery through to deployment.
• Lead engineering teams, set technical standards and make pragmatic architectural decisions that balance quality, performance and delivery.
• Design and build backend services, APIs, integrations and scalable data pipelines.
• Develop production-ready AI and machine learning solutions, including systems using Large Language Models.
• Review code and technical designs, ensuring engineering work remains maintainable, secure and fit for purpose.
• Apply modern engineering practices across Git, Docker, CI/CD and cloud-based deployments.
• Get up to speed quickly with unfamiliar scientific, engineering, operational and commercial problem spaces.
• Work closely with Defence specialists and subject matter experts to understand operational requirements and challenge assumptions where needed.
• Lead client workshops, technical discussions and project meetings with senior stakeholders.
• Translate complex operational and business requirements into clear, achievable technical strategies.
• Remove technical blockers and provide hands‑on guidance to engineers and data scientists throughout delivery.
• Support technical discovery, project scoping, bids and commercial proposals.
• Help develop reusable engineering approaches, standards and best practices across the wider technical team.
• Mentor colleagues and contribute to a culture of continuous technical development.

Main Skills Needed:

• Degree in Computer Science, Engineering, Mathematics, Physics, Statistics, Data Science or another relevant technical discipline.
• Strong track record of leading complex software, data or AI projects through the full development lifecycle.
• Previous experience within Defence, national security or another highly technical and regulated environment.
• Strong Python engineering skills with experience building high-quality production software.
• Deep understanding of software architecture, backend engineering, APIs, databases and data pipelines.
• Hands‑on experience with cloud environments such as AWS or Azure alongside Docker, Git and CI/CD.
• Practical experience designing and delivering machine learning and AI systems, including Large Language Model applications.
• Strong knowledge of software engineering principles, code quality and technical design reviews.
• Ability to quickly understand complex technical and domain‑specific challenges and turn them into practical solutions.
• Confidence leading multidisciplinary technical teams and making high‑impact engineering decisions.
• Strong client‑facing skills with experience communicating technical concepts to senior stakeholders and subject matter experts.
• Ability to mentor engineers and data scientists while maintaining high technical standards.
• Strong analytical, organisational and project planning skills.
• Existing DV clearance, or eligibility and willingness to undergo DV clearance.

What’s in It for You:

• Competitive compensation package with an annual performance bonus and equity.
• 26 days’ annual leave, plus 8 bank holidays and your birthday off.
• Enhanced family leave.
• Predominantly home‑based working with regular face‑to‑face client engagement.
• Option to work remotely from anywhere in the world for up to 4 weeks each year.
• High‑spec Windows machine or MacBook depending on your requirements.
• Regular team socials, plus free snacks and drinks when you’re in the office.
• High levels of autonomy in a supportive, entrepreneurial environment.
• Exposure to varied projects spanning software engineering, data, AI and complex Defence challenges.
• The opportunity to combine hands‑on technical work with architecture, leadership and client influence.

Big plans. Big impact. Ready to be part of it?

We are an equal opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, colour, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.