Job Title: Senior Penetration Tester (Infrastructure Focus) Location: London (Hybrid / Flexible) Salary: Up to £80,000 Bonus Benefits Employment Type: Permanent Overview 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. Key Responsibilities 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 Required Skills & Experience 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) What We Offer Salary up to £80,000 depending on experience performance bonus Strong personal development support - certifications funded and continuous training Defined career progression into CTL or Red Team positions Hybrid working with London as the preferred base