Infrastructure Penetration Tester

Deliver internal and external network and infrastructure penetration tests, including on-premises and cloud-hosted environments * Perform testing of Windows & Linux infrastructure, Active Directory, network services, and security appliances * Conduct vulnerability exploitation, privilege escalation, and lateral movement to demonstrate full attack paths * Lead small engagement teams and oversee delivery quality, documentation, and client communication * Produce high-quality, concise, and risk-aligned reports with actionable remediation guidance * Support scoping calls, stakeholder workshops, and post-engagement debriefs * Contribute to tooling, methodology enhancement, and internal research initiatives * Stay up-to-date with emerging vulnerabilities, exploits, and attacker techniques

We are seeking an experienced Senior Penetration Tester with a strong background in infrastructure security testing to join a growing offensive security team. The ideal candidate will have deep technical expertise, the ability to lead and independently deliver complex engagements, and a passion for uncovering and exploiting vulnerabilities across enterprise environments. You will play a key role in strengthening the organisation's security posture by conducting infrastructure-focused assessments, mentoring junior testers, and influencing remediation strategies., * 3-5+ years' professional penetration testing/offensive security experience * Strong understanding of enterprise infrastructure, AD security, networking, and protocols * Proficiency with tools such as Nmap, Nessus, Metasploit, BloodHound, Burp Suite, Kali/Linux toolsets * Solid track record of delivering infrastructure pentests end-to-end * Excellent communication skills, including producing business-focused reporting

Preferred Qualifications * CHECK Team Member (CSTM) or CHECK Team Leader (CTL) * CREST CRT/CCT, OSCP, OSEP, or equivalent recognised industry certifications * Experience in cloud infrastructure testing (Azure/AWS), desirable but not essential * SC or DV clearance beneficial (or eligibility to obtain it)