Software Development Engineer in Test - DV Cleared

Join a team building technology that helps keep the UK secure, resilient, and prepared for the future. Working on complex digital systems across defence and national security, you'll help deliver high-quality software that underpins critical services and mission-critical platforms.

As a Software Development Engineer in Test (SDET), you'll apply engineering principles to quality assurance by designing scalable automation frameworks, developing robust test solutions, and enabling teams to deliver software with confidence. This is an opportunity to work on technically challenging programmes where quality is fundamental to success.

The Opportunity

Our client is looking for engineers who enjoy writing code as much as they enjoy finding defects. As an SDET, you'll work closely with software engineers, DevOps specialists, architects, and business stakeholders to embed quality throughout the software development lifecycle.

You'll have the opportunity to influence technical decisions, introduce modern testing approaches, and help shape engineering best practices across large-scale delivery programmes.

Typical responsibilities include:

• Designing and implementing modern test automation frameworks for APIs, microservices, web, and front-end applications.
• Integrating automated testing into CI/CD pipelines using tools such as Azure DevOps, Jenkins, or GitHub Actions.
• Writing clean, maintainable automated tests using Java, Python, C#, or JavaScript/TypeScript.
• Collaborating with multidisciplinary delivery teams to define effective quality strategies.
• Investigating test failures, identifying root causes, and improving automation reliability.
• Contributing to engineering standards, reusable tooling, and mentoring less experienced team members where appropriate.

The systems you'll help deliver support critical national capabilities and are relied upon by millions of users in secure and mission-critical environments.

You're a collaborative, curious engineer who believes quality is everyone's responsibility.

You enjoy solving complex technical challenges, writing clean code, and building automation that adds genuine value. You communicate effectively with both technical and non-technical stakeholders and thrive in agile, collaborative environments.

Essential Skills and Experience

• CurrentUK Developing Vetting (DV) clearance.
• Strong software development skills in at least one of the following:

• Java
• C#
• Python
• JavaScript / TypeScript

• Experience designing, building, or extending automated testing frameworks across API, web, or mobile applications.
• Hands-on experience with test automation tools such as Selenium, Playwright, RestAssured, Appium, or Cucumber.
• Experience using version control systems such as Git.
• Experience working within Agile delivery teams using tools such as Jira or Azure DevOps.
• Strong communication skills and a collaborative approach to engineering.

Desirable Skills

• Experience implementing automated testing within CI/CD pipelines.
• Understanding of microservices and containerised architectures.
• Experience working with cloud platforms such as AWS, Azure, or Google Cloud Platform.
• Knowledge of performance, security, or accessibility testing.
• Experience with infrastructure-as-code or container technologies including Docker, Kubernetes, or Terraform.
• Contributions to open-source projects or technical communities.

• Opportunity to work on technically challenging programmes with real-world impact.
• Collaborative engineering environment focused on quality, innovation, and continuous improvement.
• Ongoing professional development and access to modern technologies and engineering practices.
• Hybrid working model based from London, with a blend of office, client-site, and remote working depending on project requirements.
• A culture that values inclusion, collaboration, wellbeing, and continuous learning.