Pentester / Red Team Specialist

Claranet limited; Lisboa; Hybrid; EUR 55,000 - 90,000; Full time

Job summary

Claranet limited in Lisbon is seeking a Pentester / Red Team Specialist to join our internal security team, based in Lisbon, with a hybrid work model.

You will perform comprehensive penetration tests across internal and external infrastructures, web applications, APIs, and cloud environments; produce clear technical reports with actionable mitigations; present results to clients, and contribute to methodologies, tooling, and knowledge sharing within the team.

Qualifications

• 3 to 5 years of experience in Pentesting, Offensive Security, Red Teaming, or similar roles.

Responsibilities

• Perform penetration tests on internal and external infrastructures, web applications, APIs, cloud environments, and identity platforms;

Skills

Pentesting

Security testing

OWASP / NIST / MITRE

Burp Suite / Nmap

Windows / Linux

Cloud security

Automation scripting

Reporting

Communication

Tools

Burp Suite

Nmap

Metasploit

Job description

We're fast learners, hard workers, natural collaborators... and we Make Modern Happen!

Our ambition is to unlock the potential of our digital world so that organisations everywhere can innovate and thrive securely. We aim to achieve this goal by bringing together the world's most talented people and the most powerful technologies, combining them to address our customers' challenges and build something stronger together. If you share our vision, join us!

Right now, we are looking for a Pentester / Red Team Specialistto integrate our internal team, based in Lisbon.

Your responsibilities include:

• Perform penetration tests on internal and external infrastructures, web applications, APIs, cloud environments, and identity platforms;
  
• Identify attack vectors, validate vulnerabilities, and assess realistic attack paths;
  
• Conduct manual security assessments beyond automated scanning tools;
  
• Evaluate exploitation feasibility and business impact to support risk prioritization;
  
• Produce clear, actionable technical reports with mitigation recommendations;
  
• Present assessment results to customers and support remediation discussions;
  
• Take ownership of security assessments from planning to final delivery;
  
• Leverage AI-powered tools to enhance research, analysis, and automation while validating outputs;
  
• Contribute to methodologies, playbooks, tooling, and knowledge-sharing initiatives;
  
• Participate in Red Team and Purple Team exercises when required.
  

You must have:

• 3 to 5 years of experience in Pentesting, Offensive Security, Red Teaming, or similar roles;
  
• Hands-on experience with infrastructure, web application, and API security testing;
  
• Strong knowledge of OWASP Top 10, OWASP WSTG, PTES, NIST, and MITRE ATT&CK frameworks;
  
• Experience with tools such as Burp Suite, Nmap, Metasploit, or equivalent;
  
• Good understanding of Windows, Linux, networking, and authentication mechanisms;
  
• Knowledge of Active Directory, Entra ID, and cloud security concepts;
  
• Scripting or programming skills for automation and tool development;
  
• Ability to analyse findings critically, distinguish false positives, and support conclusions with technical evidence;
  
• Strong communication and reporting skills.
  

Nice to have:

• Experience with Mobile Pentesting and Wi-Fi Assessments;
  
• Exposure to Adversary Simulation, Red Team, or Purple Team exercises;
  
• Vulnerability research and offensive tooling development experience;
  
• Offensive Security certifications such as OSCP, OSWE, OSWA, CRTO, eWPT, or equivalent;
  
• Experience presenting technical findings to clients and stakeholders.
  

We offer:

• Certification paths resources.
  
• Regular team building programs.
  
• Friendly workplace.
  

Workplace:

Lisbon - Hybrid (2 days at office)