Job Specifications
Senior Penetration Tester (CTL / CSTL) | CHECK | Remote (UK) | 20% Travel
Location: United Kingdom (Fully Remote) - Travel across the UK (approx. 20%), fully expensed
Package: £80,000 – £100,000 base salary + Excellent Benefits
Eligibility: Must hold UK residency + valid SC Clearance and CHECK certification (CTL or CSTL)
Travel: Role includes up to 15/20% UK travel to client sites across The UK (all expenses covered)
Please only apply if you have ALL the following
6+ years’ hands-on penetration testing experience
Current CTL or CSTL status (held for 2+ years)
Active SC Clearance
CHECK certification (CTL / CSTL / CSTM - you must hold CHECK status, we will verify)
Strong track record delivering advanced pen testing across infrastructure and/or applications
Ability to work independently in senior-level client-facing environments
Willingness to travel approximately 15/20% across the UK
Required Background
6+ years’ industry experience in offensive security / penetration testing
Demonstrable depth in at least one of the following:
Infrastructure Pen Testing
Application / Web App Pen Testing
Strong knowledge of modern attack techniques, tooling, and methodologies
Experience delivering reports, presenting findings, and advising on remediation
Exposure to large-scale enterprise, government, or regulated environments
Ability to run complex engagements end-to-end with minimal oversight
Clear understanding of threat modelling, risk assessment, and senior stakeholder communication
ℹ Very Important Notes
You MUST hold CTL or CSTL status (CHECK-approved)
You MUST hold SC Clearance
This is a senior, hands-on role - not suitable for juniors or mid-level testers
The role includes UK-wide travel (approx. 20%), fully expensed
Dual-skilled CTLs (Infrastructure + Apps) will be considered for the top salary band
Strong communication and client-facing professionalism is essential
Must-Haves (Non – negotiable)
CTL or CSTL status held for minimum 2 years
CHECK registration (CTL / CSTL / CSTM — must confirm you hold CHECK status)
Deep technical proficiency in offensive security
Ability to scope, plan, execute, and deliver high-quality testing engagements
Strong reporting, documentation, and advisory capabilities
Experience working with enterprise or government clients
SC Cleared
UK-based and eligible to work & travel freely
Stable career history and proven delivery of long-term engagements
Bonus Experience
Dual-skilled CTL (Infrastructure + Applications)
Experience mentoring or guiding junior testers
Red Teaming exposure
Experience with tooling and automation for testing
Knowledge of cloud security (AWS/Azure)
Threat intelligence or purple team collaboration experience
Hands-On Experience With
Infrastructure penetration testing
Web and application penetration testing
Advanced exploitation, enumeration, and privilege escalation
Reporting to CHECK standards
Vulnerability assessment tooling
Manual testing methodologies aligned to industry best practice
Working with clients across public sector, enterprise, or highly regulated industries
What You’ll Be Doing
Pen Testing & Delivery
Deliver high-quality penetration testing engagements (infrastructure, applications, cloud etc.)
Execute senior-level testing aligned to CHECK requirements
Provide in-depth, quality reporting with remediation guidance
Lead or contribute to multi-scope testing assignments
Quality & Ownership
Ensure testing is delivered to the highest technical and professional standard
Maintain CHECK-level methodologies and best practices
Support continuous improvement in offensive security approaches
Client Interaction
Present findings and recommendations to technical and non-technical stakeholders
Work directly with engineering, security, and leadership teams
Provide expert guidance, advisory support, and risk insight
If you meet all the above essentials and are a highly capable Senior Penetration Tester with CTL/CSTL and SC, get in touch for an immediate conversation.
About the Company
At Optimal, recruitment is more than just matching candidates with roles - it's about building lasting relationships and thriving communities.
Our founder, with over 20 years of technical IT recruitment experience, is a passionate advocate for community engagement and the organiser of the first-ever London Ministry of Testing Meetup. Combining technical expertise with a CT-AI certification, they have made Optimal a true recruitment specialist.
Our core expertise lies in Test, Development, and Quality Engineering. Additiona...
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