Software Engineer

What You’ll Do

• Lead the design and development of desktop, web, or service-based applications.

• Architect and implement high quality Python code, application frameworks, APIs, and supporting automation.

• Develop and maintain modern user interfaces and desktop/web applications using Vue and Electron.

• Develop solutions that integrate data processing, UI/UX, automation, and system level components.

• Create, maintain, and improve infrastructure as code using Ansible and Terraform/Terragrunt.

• Lead testing, debugging, optimisation, and performance improvements.

• Shape requirements, propose technical approaches, and influence project direction.

• Support integration and deployment of software into secure operational environments.

• Build and support CI/CD pipelines in GitLab to automate testing, packaging, deployment, and release activities.

• Work with supporting platform components, including MongoDB, Elasticsearch, Redis, RabbitMQ and related integration services.

• Occasionally support installation, configuration, and commissioning of hardware in secure environments.

• Engage directly with users to understand operational challenges and deliver effective solutions.

• Produce high quality documentation and maintain traceable, peer reviewed git practices, aligned with repository governance policies.
• Mentor junior developers and contribute to team knowledge sharing.

What You’ll Bring

Essential:

• Extensive experience in software development for applications or tools.

• Strong proficiency in Python and the ability to work across modern application frameworks and automation tooling.

• Experience designing and delivering production quality applications.

• Strong understanding of UI frameworks, APIs, data handling, system integration, and secure application design.

• Confident working in Linux and/or MacOS development environments.

• Ability to work flexibly across multiple programming languages and frameworks.

• Proven ability to solve complex technical problems with creativity and rigour.

• Ability to influence technical decisions and collaborate across teams.

• Experience with testing frameworks, debugging tools, Git workflows, and CI/CD pipelines, ideally using GitLab.

• Working knowledge of good industry practice for secure coding, application security, and security-conscious development lifecycles.

• Experience with infrastructure as code, particularly Ansible and Terraform/Terragrunt.

• Experience working with MongoDB, Elasticsearch, Redis, RabbitMQ, or similar data and messaging technologies.

Desirable:

• Experience in secure or defence related environments.

• Knowledge of cryptography, secure data handling, or secure system design.

• Experience with web or desktop frameworks, particularly Vue and Electron, alongside Python web frameworks such as Flask, FastAPI, or Django.

• Familiarity with containerisation, virtualisation, secure deployment practices, and operational support in controlled environments.

• Practical experience installing, configuring, or troubleshooting hardware where software delivery depends on physical infrastructure.

• Experience with distributed systems or message‑based architectures.

Education and Experience

• Degree in Computer Science, Software Engineering, or related field preferred.
• Professional membership (BCS, IET) is a plus.

Why Leidos?

We’re a global technology company tackling the UK’s toughest national security challenges. Our Capability Development team is known for delivering bespoke, high-performance solutions in complex environments. We value people who are curious, self-directed, and eager to get their hands dirty with code.

What We Offer

• Competitive Salary & Financial Rewards: Pension, share options, car leasing, free parking, cycle scheme.
• Private Medical Insurance
• 33 Days Annual Leave (incl. public holidays), with buy/sell options.
• Flexible Benefits: Life assurance, gym memberships, health plans.
• Work-Life Balance: 37.5-hour week + up to 2 TOIL days per month.
• Learning & Development: TechX Academy, unlimited e-learning, career mobility.
• Flexi time working

If you want to work on real-world systems, close to the mission, and in a role where your code directly impacts outcomes, we’d love to hear from you.

At Leidos we are PASSIONATE about customer success, UNITED as a team and INSPIRED to make a difference. We offer meaningful and engaging careers, a collaborative culture, and support for your career goals, all while nurturing a healthy work-life balance.
We provide an employment package that attracts, develops and retains only the best in talent.

Commitment to Diversity:

We welcome applications from every part of the community and are committed to a truly diverse and inclusive culture. We foster a sense of belonging, welcoming all perspectives and contributions, and providing equal access to opportunities and resources for everyone. If you have a disability or need any reasonable adjustments during the application and selection stages please let us know, and we will respond in a way that best fits your needs.

Who We Are:

Leidos UK & EUROPE – we work to make the world safer, healthier, and more efficient through technology, engineering and science.

Leidos is a growing company delivering innovative technology and solutions focused on safeguarding critical capabilities and transformation in frontline services, our work in the United Kingdom includes addressing some of the most complex problems in defence, healthcare, government, safety and security, and transportation.

What Makes Us Different:

Purpose: you can use your passion and abilities at Leidos to keep the people you care about safe. We are at the forefront of machine learning, AI, cyber security and solutions. Using your skills in the technology frontline by helping to build a safer world. You can inspire change.

Collaboration: having flexibility to do your job is one of our core benefits, enabling you to become part of our extraordinary team. We have been empowering our people to work flexibly for years. Whether you work from home, the office or on customer sites, we will give you the digital tools and the flexibility to work smarter and align your needs and ours.

People: Leidos empowers people from every background to be themselves and gives you the tools to learn new skills by enabling growth whilst developing. We believe that extraordinary people need opportunities to grow, to be inspired and to inspire others. At Leidos, we invest in technical academies, career rotations and a career development plans that enhance your future. #INTNSD

If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.

Original Posting:

For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.

Pay Range:

£61,500.00-£78,800.00

The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.