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# Penetration Tester

- **Company:** Barclay Simpson
- **Location:** London, United Kingdom (Remote available)
- **Experience:** Expert
- **Salary:** £143,000 - £156,000
- **Contract:** Permanent contract
- **Skills:** Software as a Service, Cyber Security, Computer Telephony Integration, Cyber Threat Analysis
- **Published:** November 3, 2026
- **Apply:** https://www.barclaysimpson.com/job/jem-44760/penetration-tester/

## About the Role

* Minimum 3 years' experience in penetration testing and cyber security.
 * Strong experience in:
 + Web application penetration testing
 + Infrastructure and network penetration testing
 + Network security architecture and design
 + Vulnerability assessment across operating systems, software, protocols, and networks
 * Experience researching and evaluating security technologies, tools, and products.
 * Solid knowledge of UNIX/Linux and Windows system administration.
 * Proficiency with industry-standard penetration testing tools, techniques, and methodologies.
 * Scripting experience in at least one of the following:
 + Python
 + Perl
 + Ruby
 + Bash/Shell scripting
 * Strong understanding of:
 + Network and system security
 + Authentication and security protocols
 + Cryptography
 + Application security
 + Malware techniques and defensive technologies
 * Ability to assess risk, communicate findings effectively, and develop practical mitigation strategies., Please note: Candidates must hold NATO Secret clearance or UK Security Check (SC) clearance to be considered for this position. You must also be fluent in English.

## Description

* Lead and participate in Red Team and Blue Team activities during NATO military exercises.
 * Conduct web application, infrastructure, and application penetration testing across a range of environments.
 * Perform security assessments and design reviews to ensure compliance with NATO security policies, standards, and directives.
 * Provide expert security consultancy and technical guidance to projects, programmes, and operational teams.
 * Identify security vulnerabilities within operating systems, applications, networks, and protocols, providing clear remediation recommendations.
 * Support security accreditation activities and collaborate with key stakeholders throughout the accreditation lifecycle.
 * Build and maintain strong working relationships with internal and external stakeholders, including:
 + NCIA Configuration Control Board
 + Security Accreditation Boards
 + NATO Security Accreditation Authorities
 + NCI Agency organisational units