Penetration Tester in Horsham

Are you an experienced Penetration Tester looking to take the next step in your offensive security career? This is an exciting opportunity to join a collaborative Cyber Defence team where you'll deliver hands-on security testing across web applications, APIs, infrastructure, and cloud environments while working alongside experienced security professionals. You'll play a key role in identifying vulnerabilities, supporting remediation, contributing to purple team exercises, and helping shape security best practice across the organisation. This role offers excellent opportunities to develop your technical expertise, work with modern security tooling, and progress towards senior offensive security positions.

Key Responsibilities:

• Deliver penetration testing across web applications, APIs, infrastructure, and cloud environments using recognised industry methodologies.
• Perform end-to-end testing activities including reconnaissance, exploitation, post-exploitation, validation, and reporting.
• Produce clear, risk-based penetration testing reports with practical remediation recommendations for both technical and non-technical stakeholders.
• Support the management of external penetration testing providers, reviewing test quality, validating findings, and ensuring consistency of deliverables.
• Assist with vulnerability assessments, risk prioritisation, remediation tracking, and re-testing activities.
• Work closely with development, engineering, and delivery teams to embed security testing into project lifecycles and advise on appropriate testing approaches.
• Contribute to purple team exercises, incident investigations, and wider Cyber Defence initiatives.
• Help improve internal testing methodologies, playbooks, tooling, and knowledge sharing across the team.
• Maintain awareness of emerging threats, vulnerabilities, attacker techniques, and offensive security tools.

Key Requirements:

• Previous hands-on experience as a Pen Tester delivering assessments across web applications, APIs, infrastructure, and cloud environments.
• Strong understanding of common vulnerability classes, including the OWASP Top 10, authentication and authorisation flaws, input validation issues, and business logic vulnerabilities.
• Knowledge of penetration testing methodologies such as OWASP, PTES, and NIST, with practical experience using offensive security tools.
• Experience interpreting vulnerability scan results and validating security findings.
• Understanding of attacker tactics, techniques, and procedures, and how they apply in real-world scenarios.
• Ability to produce clear, well-structured technical reports with risk-based remediation advice.
• Holds, or is working towards, a recognised penetration testing certification such as CREST CPSA/CRT, OSCP, or equivalent experience.
• Strong communication skills with the ability to build relationships across technical and business teams.
• Analytical, organised, collaborative, and passionate about offensive security with a proactive approach to continuous learning.