Penetration Tester

Capital One
London

White Collar Factory (95009), United Kingdom, London, London

Penetration Tester

About the role

Capital One Offensive Security reduces cyber risk by uncovering vulnerabilities and weaknesses in the enterprise cyber environment through coordinated ethical hacking and penetration testing scenarios. This position works closely with team members to plan, coordinate, execute and report on sophisticated ethical hacking exercises, to identify cyber vulnerabilities and reduce the risk posture of enterprise systems. This role will be primarily responsible for performing application and network security assessments and will make recommendations to management on effective countermeasures.

The successful candidate for this position will be part of an exciting and dynamic environment to build and deliver industry leading ethical hacking capabilities to continuously protect and defend Capital One brand, systems and data. Offensive Security is part of the Cyber Operations and Intelligence program and assists with identifying opportunities to enhance Capital One’s information security posture against a broad range of cyber threats, and develop strategies to most effectively address the threats.

This position is to be located in either London or London.

What you’ll do:

  • Perform penetration testing of APIs, web applications, networks, and cloud services, as well as related applications and infrastructure.

  • Assess Capital One’s development practices and help drive corporate security standards.

  • Help triage and test application responsible disclosure findings and newly disclosed vulnerabilities.

  • Work with developers to improve the Software Development Lifecycle (SDLC) for applications.

  • Present findings, risks and conclusions to technical and non-technical audiences.

  • Collaborate closely with the business throughout remediation including influencing stakeholders and delivery teams on prioritization of security activities and issue remediation.

  • Establish effective and productive relationships with colleagues across the Global Cyber organization and technology departments as well as the UK business.

What we’re looking for:

  • Information security experience in one or more of the following areas: red teaming, penetration testing, application security, or network security.

  • Strong knowledge of Web, API and mobile application security testing frameworks and methodologies.

  • Familiarity with penetration testing tools such as BurpSuite, OWASP Zap, SoapUI etc.

  • Strong knowledge of application security best practices including OWASP Top 10.

  • Should have a strong understanding of networking concepts, Windows, Linux and Mac operating systems, cloud and web application vulnerabilities and exploitation.

  • Experience with threat modeling concepts and frameworks (CVSS, MITRE ATT&CK, DREAD, or STRIDE)

  • Technical knowledge in software engineering, system and network security, authentication and security protocols, cryptography, and network/web related protocols (e.g., TCP, UDP,

Any of these would be advantageous (but we'd still love to hear from you):

  • Bachelors Degree or equivalent certification

  • Security testing of cloud environments. We’re invested with AWS but will consider those who have worked on any other major public cloud provider (Azure, GCP).

  • Experience in offensive security tool development, customization or expansion.

  • Ability to code comfortably in one or more interpreted languages (eg. Python, Bash, PowerShell, Perl, Ruby) and one or more compiled languages (eg. C, C++, C#, Golang, Rust, Java, Objective-C)

  • Penetration testing experience with Internet of Things ( IoT) devices, mobile applications, or code review.

  • One or more of the following certifications (OSCP, OSCE, GPEN, GXPN, CRTO, CREST Certified Simulated Attack Manager)

Where and how you'll work

This is a permanent position and can based in either our London or Nottingham Head Offices.

We have a hybrid working model which gives you flexibility to work from our offices and from home.

We’re big on collaboration and connection, so you’ll be based in either our London or Nottingham Head Offices 3 days a week.

Many of our associates have flexible working arrangements, and we're open to talking about an arrangement that works for you.

What’s in it for you

  • Bring us all this - and you’ll be well rewarded with a role contributing to the roadmap of an organisation committed to transformation

  • We offer high performers strong and diverse career progression, investing heavily in developing great people through our Capital One University training programmes (and appropriate external providers)

  • Immediate access to our core benefits including pension scheme, bonus, generous holiday entitlement and private medical insurance – with flexible benefits available including season-ticket loans, cycle to work scheme and enhanced parental leave

  • Open-plan workspaces and accessible facilities designed to inspire and support you. Our Nottingham head-office has a fully-serviced gym, subsidised restaurant, mindfulness and music rooms. In London, you can heighten your mood with a run on our rooftop running track or an espresso at the Workshop Coffee café

What you should know about how we recruit

We pride ourselves on hiring the best people, not the same people. Building diverse and inclusive teams is the right thing to do and the smart thing to do. We want to work with top talent: whoever you are, whatever you look like, wherever you come from. We know it’s about what you do, not just what you say. That’s why we make our recruitment process fair and accessible. And we offer benefits that attract people at all ages and stages.

We also partner with organisations including the Women in Finance and Race At Work Charters, Stonewall and upReach to find people from every walk of life and help them thrive with us. We have a whole host of internal networks and support groups you could be involved in, to name a few:

  • REACH – Race Equality and Culture Heritage group focuses on representation, retention and engagement for associates from minority ethnic groups and allies

  • OutFront – to provide LGBTQ+ support for all associates

  • Mind Your Mind – signposting support and promoting positive mental wellbeing for all

  • Women in Tech – promoting an inclusive environment in tech

  • EmpowHER - network of female associates and allies focusing on developing future leaders, particularly for female talent in our industry

Capital One is committed to diversity in the workplace.

If you require a reasonable adjustment, please contact [email protected] All information will be kept confidential and will only be used for the purpose of applying a reasonable adjustment.

For technical support or questions about Capital One's recruiting process, please send an email to [email protected]

Capital One does not provide, endorse nor guarantee and is not liable for third-party products, services, educational tools or other information available through this site.

Capital One Financial is made up of several different entities. Please note that any position posted in Canada is for Capital One Canada, any position posted in the United Kingdom is for Capital One Europe and any position posted in the Philippines is for Capital One Philippines Service Corp. (COPSSC).

Who We Are

At Capital One, we're building a leading information-based technology company. Still founder-led by Chairman and Chief Executive Officer Richard Fairbank, Capital One is on a mission to help our customers succeed by bringing ingenuity, simplicity, and humanity to banking. We measure our efforts by the success our customers enjoy and the advocacy they exhibit. We are succeeding because they are succeeding.

Guided by our shared values, we thrive in an environment where collaboration and openness are valued. We believe that innovation is powered by perspective and that teamwork and respect for each other lead to superior results. We elevate each other and obsess about doing the right thing. Our associates serve with humility and a deep respect for their responsibility in helping our customers achieve their goals and realize their dreams. Together, we are on a quest to change banking for good.
Posted 2026-02-03

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