Application Security Test Engineer in Oxford

Our goal is to bring the widest benefits to society by enabling the analysis of anything, by anyone, anywhere. We have developed a new generation of nanopore‑based sensing technology that provides faster, information‑rich, accessible, and affordable molecular analysis. This technology is currently applied to DNA/RNA sequencing and is being expanded to proteins and other molecules. It is used to understand biology across humans, diseases such as cancer, plants, animals, bacteria, viruses, and entire environments, and we strive to improve life on Earth.

We are seeking an Application Security Test Engineer to join our Instrument Software Test team. In this role, you will help ensure the security and quality of ONT’s desktop and platform software, which runs across Linux, Windows, and macOS and plays a critical role in controlling sequencing instruments and processing complex scientific data. This hands‑on role is suited to someone with practical experience in software or application security testing who is keen to deepen their expertise in a technically challenging, real‑world environment. You will work closely with developers, product owners, and fellow testers to identify security risks, validate mitigations, and continuously improve how we test for security across the software development lifecycle. You won’t be expected to define company‑wide security policy, but you will independently drive security testing activities within your area, apply good security judgement, and continuously improve how we test for security issues.

Key responsibilities

• Perform application security testing of desktop applications, background services, and supporting tooling.
• Test across Linux, Windows, and macOS, including installers, configuration, permissions, logging, secrets handling, and update mechanisms.
• Identify vulnerabilities through exploratory testing, dynamic analysis, misuse scenarios, and security tooling.
• Design and maintain security‑focused test cases based on requirements, architecture, and risk.
• Produce clear, high‑quality vulnerability and defect reports, and work with developers to validate fixes and prevent regressions.
• Use and contribute to security testing tools, scripts, and automated checks where appropriate.
• Collaborate within Agile, cross‑functional teams to ensure security considerations are embedded throughout development.
• Prioritise testing activities based on risk, impact, and delivery timelines, while considering end‑user experience.

You might be a good fit if you have:

• Experience in software security testing, application security, or software testing with a strong security focus.
• Hands‑on experience testing desktop or platform software on Linux and/or macOS (Windows experience is beneficial).
• Understanding of common security vulnerability types and risk‑based testing approaches.
• Experience using security testing tools such as intercepting proxies, vulnerability scanners, or dependency analysis tools.
• Ability to write scripts or small tools to support testing.

Nice to have:

• Familiarity with containerised or data‑intensive software environments.
• Experience testing desktop or hardware‑adjacent software.
• Exposure to automated testing, CI pipelines, or security tooling.
• Experience testing software that interacts with hardware or processes large volumes of data.
• Familiarity with modern build or development toolchains.

As liaising with a variety of collaborators is a regular part of this role, we’re looking for someone with excellent verbal and written communication skills and an approachable manner that encourages interaction with others. You also need a good eye for detail and excellent organisational abilities to meet tight deadlines. This role will suit someone who works well under pressure, and who wants the challenge of being part of a fast‑paced high‑tech organisation. You will sometimes need to work with the team at our Oxford offices; therefore you must be able to commute to our HQ based in Oxford.

We offer outstanding benefits to include an attractive bonus, generous pension contributions, private healthcare and an excellent starting salary. If you are looking to utilise your skills to really make a difference to humankind, then consider joining our team and apply today!