Infrastructure Penetration Tester | CHECK | Crest | CSTL/CTL | Networking | Config

Infrastructure Penetration Tester | CHECK | Crest | CSTL/CTL | Networking | Config Reviews | API Testing | Contract
Pen Testing | Infrastructure | External & Internal Networks 

SR2 is partnered with a leading security consultancy on a significant multi-phase testing programme, and we're looking for an experienced Infrastructure Penetration Tester to join the team.
This role will focus on delivering hands-on penetration testing across external and internal networks, reviewing system configurations, and identifying vulnerabilities within critical infrastructure. You'll work alongside a small team of experienced testers to support a major client undergoing large-scale change, ensuring their environment is secure and compliant.

Key Responsibilities:

• Conduct comprehensive external and internal infrastructure penetration tests, starting with perimeter systems and moving into internal networks
• Perform configuration reviews across Servers, Firewalls, Routers, and network devices
• Execute API security testing to assess authentication, data access, and integration risks
• Deliver "old-school" CHECK-style network and infrastructure testing in line with industry standards
• Produce detailed technical reports outlining vulnerabilities, exploitation paths, and remediation guidance
• Collaborate with the project lead and wider team across a six-phase testing programme
• Engage directly with stakeholders and SMEs to ensure smooth onboarding and delivery

Skills & Experience Required:

• Proven background in infrastructure penetration testing within complex network environments
• Crest certification or CHECK Team Member/CHECK Team Lead (CTM/CTL) status advantageous
• Strong understanding of networking, configuration management, and common attack vectors
• Experience performing API and configuration reviews
• Excellent report writing and communication skills for both technical and non-technical audiences
• Ability to work on-site in London for key phases of testing
• Collaborative mindset, comfortable working as part of a small testing team (3-4 people)

The Details:

• Contract role - IR35 Outside
• Rate: market rate
• Location: West London
• Start: Within 2-3 weeks
• Length: 6 months

If you're am Infrastructure penetration tester with experience across networks, configurations, and APIs, and you're looking for a hands-on role in a collaborative team delivering a major London-based project, apply now for immediate consideration.