Senior Penetration Tester: Lead Offensive Security

Hamilton Barnes; Greater London; On-site; GBP 50,000 - 65,000; Full time

Job summary

Hamilton Barnes is seeking a Senior Penetration Tester to perform hands-on testing across infrastructure, networks, web applications and APIs for varied client environments. The role emphasizes contributing to an offensive security function rather than sole test delivery.

You will deliver tests, identify vulnerabilities, and produce detailed client reports while mentoring junior testers and helping evolve testing methodologies.

Qualifications

• 3+ years of commercial penetration testing experience.
• Experience with offensive security methodologies.
• Infrastructure, network and web application testing experience.
• Good understanding of Active Directory and Windows.
• Experience with Burp Suite, Nmap, Metasploit and Kali.
• Scripting experience with Python, PowerShell or Bash.
• Strong communication and client-facing skills.
• Curious, technically minded and solution-oriented approach.

Responsibilities

• Deliver infrastructure, network, web and API penetration tests.
• Identify and exploit vulnerabilities and realistic attack paths.
• Conduct manual testing alongside automated tooling.
• Produce clear, technically detailed client reports.
• Present findings and remediation advice to clients.
• Contribute to offensive security methodologies and tooling.
• Support junior testers and share technical knowledge.

Skills

Penetration testing

Offensive security

Infrastructure testing

AD/Windows

Burp Suite

Nmap

Metasploit

Kali

Python

PowerShell

Bash

Client-facing

Curious mind

Tools

Burp Suite

Nmap

Metasploit

Kali

Job description

Hamilton Barnes is seeking a Senior Penetration Tester to perform hands-on testing across infrastructure, networks, web applications and APIs for varied client environments. The role emphasizes contributing to an offensive security function rather than sole test delivery.

You will deliver tests, identify vulnerabilities, and produce detailed client reports while mentoring junior testers and helping evolve testing methodologies.