Lead Penetration Tester
Instil
Posted: January 12, 2026
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Quick Summary
We're looking for a highly skilled Lead Penetration Tester with CHECK Team Lead (CTL) status to join our dynamic security team. This is a senior, hands-on role where you'll lead and deliver complex penetration testing engagements across infrastructure, cloud, web, and mobile applications for a diverse range of clients. You'll play a pivotal role in shaping our offensive security services, coordinating end-to-end testing, mentoring junior testers, and contributing to the evolution of our methodology.
Required Skills
Job Description
We’re looking for a highly skilled Lead Penetration Tester with CHECK Team Lead (CTL) status to join our dynamic security team. This is a senior, hands-on role where you’ll lead and deliver complex penetration testing engagements across infrastructure, cloud, web, and mobile applications for a diverse range of clients, including software, fintech, manufacturing, engineering, legal, and public sector organisations.
You’ll play a pivotal role in shaping our offensive security services, coordinating end-to-end testing, mentoring junior testers, and contributing to the evolution of our methodologies. If you thrive on tackling challenging security problems, enjoy working in a collaborative environment, and want to keep pushing your technical boundaries, we’d love to hear from you.
What You’ll Do
• Lead and execute penetration tests across infrastructure, cloud, web, and mobile applications.
• Manage end-to-end engagements: from scoping and kick-off sessions to delivery and client debriefs.
• Produce detailed, actionable reports outlining vulnerabilities and tailored remediation steps.
• Stay ahead of emerging threats by researching new offensive techniques and integrating them into our methodology.
• Automate repetitive tasks and streamline testing processes through scripting.
• Mentor and coach junior testers, supporting their technical growth and career development.
• Enhance tools and methodologies, ensuring our services remain cutting-edge.
• Support pre-sales efforts as a subject-matter expert in penetration testing.
• Communicate findings effectively to both technical and non-technical stakeholders.
• Contribute to thought leadership through blogs, white papers, or speaking engagements.
Essential Skills
• CHECK Team Lead (CTL) status - Infrastructure or Web Applications
• Current UK SC Clearance.
• Minimum 5 years’ penetration testing experience, with a proven track record of complex engagements.
• Proven experience in cloud security reviews (AWS, Azure, GCP).
• Deep expertise in web, mobile, and network penetration testing methodologies.
• Advanced knowledge of operating systems (Linux, Windows, Active Directory).
• Familiarity with cloud environments and ability to perform cloud security reviews.
• Proficiency with tools such as BurpSuite Pro, Nmap, Nessus, Metasploit, and Kali Linux.
• Strong scripting skills (Python, Shell, etc.).
• Excellent communication and technical report writing skills.
Nice-to-Have
• Additional certifications: OSCP, CSTL/CCT, Cyber Scheme, CREST.
• UK Cyber Security Council Chartership (Principal or above).
• Experience with Hack The Box or Capture the Flag simulations.
• Exposure to advanced testing techniques and red team engagements.
Why Join Instil?
At Instil, we believe great work starts with happy, motivated people. That’s why we’ve built a benefits package that supports your wellbeing, growth, and life outside of work, because when you thrive, so do we.
• Recognition That Matters: A discretionary annual performance bonus that rewards your impact and contribution to our success.
• Flexibility Built In: Flexible working arrangements and summer hours, because life isn’t 9 to 5, and balance matters.
• Financial Security: A highly competitive pension scheme with generous employer contributions, private healthcare, and life assurance for peace of mind.
• Health & Wellbeing: Employee Assistance Programme, mental health support, cycle-to-work scheme, and regular social events to keep our culture vibrant.
• Time to Recharge: 35 days holiday, enhanced maternity pay, and family-first policies so you can focus on what matters most.
• Learning Never Stops: From courses to certifications, we’ll invest in your development so you can keep growing and shaping what’s next.
• Community & Culture: Opportunities to volunteer, give back, and be part of initiatives that make Instil a truly inclusive and connected workplace.
And that’s just the start, drop us a note to find out more.
Company Description
Instil has been delivering world-class software engineering and technology solutions for over 20 years, trusted by global brands to solve complex challenges and drive innovation. From modernising legacy systems to building cutting-edge applications, we help our clients navigate an ever-changing digital landscape with confidence and agility.
We’re proud to be an award-winning employer, reflecting how our people are at the heart of everything we do:
• Recognised as a Great Place to Work® for three consecutive years, and in 2024 ranked in the Top 20 Best Workplaces in the UK for medium-sized companies.
• Winner of Company of the Year at the Digital DNA Awards 2022, celebrating excellence in Northern Ireland’s tech sector.
Driven by a love for technology and a commitment to excellence, we bring together people who want to make a difference. We’ll support your journey, because your success is part of ours.
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