Penetration Tester – Offensive Security

Uni Systems

. Perform internal and external infrastructure penetration testing covering networks, systems and Active Directory environments .

Posted 11/11/2026full-timeAthens • GreeceMid-LevelSeniorWebsite

Core Competencies

Role fit

Core Competencies

Use this summary to align your resume positioning with the role.

Demonstrates expertise in Penetration Testing and Offensive Security, with a strong focus on Web Application and API vulnerabilities, vulnerability assessments, and security reporting. Proficient in scripting and automation to enhance penetration testing activities and communicate findings effectively to stakeholders.

Highest-signal resume keywords

Penetration TestingVulnerability AssessmentWeb Application/API SecurityScripting with PythonSecurity Source Code Review

ATS Keywords

Tailor your resume

Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard Skills

Penetration TestingVulnerability AssessmentWeb Application SecurityAPI SecurityActive Directory SecurityNetworking ConceptsManual TestingExploitation TechniquesSecurity MethodologiesCloud Security Assessments

Soft Skills

Clear CommunicationTechnical ReportingClient Interaction

Tools & Technologies

Burp SuiteNmapMetasploitNessusOWASP WSTGPTESFirewallsIDS/IPSWAFsVPNs

Certifications & Qualifications

OSCPCEHCPTSPNPTECPPTEWPTCRESTGPENGWAPTBSCP

Industry Keywords

Offensive SecurityRed Team OperationsMobile Application Penetration TestingSocial Engineering AssessmentsOWASP Top 10OWASP API Security Top 10Information SecurityComputer ScienceInformation TechnologySecurity Assessments

Tech Stack

Tools & technologies

AWSAzureCloudFirewallsLinuxPython

About the role

Key responsibilities & impact

Perform internal and external infrastructure penetration testing covering networks, systems and Active Directory environments
Conduct Web Application and API penetration testing using black-box, grey-box and white-box approaches
Perform vulnerability assessments, analyze scan results and manually validate identified vulnerabilities, including controlled exploitation where appropriate
Participate in Security Source Code Reviews to identify vulnerabilities and insecure coding practices
Prepare penetration testing and vulnerability assessment reports with technical findings, supporting evidence, risk assessment and remediation recommendations
Perform re-testing to verify that identified vulnerabilities have been addressed
Explain and demonstrate the technical and business impact of identified vulnerabilities to clients
Develop or customize scripts and tools to support penetration testing activities
Participate in planning and executing security assessments according to the agreed scope, testing methodology and Rules of Engagement
Support specialized engagements including Red Team operations, Mobile Application Penetration Testing and Social Engineering assessments

Requirements

What you’ll need

University/College degree in Information Security, Computer Science, Information Technology or a related discipline, or equivalent practical experience
3+ years of hands-on experience in Penetration Testing or Offensive Security
Hands-on experience in Web Application/API or Infrastructure Penetration Testing, with working knowledge of the other area
Experience in vulnerability assessments, manual testing and exploitation techniques
Familiarity with Security Source Code Review and common application security weaknesses
Good knowledge of Windows and Linux operating systems, networking concepts and Active Directory security
Understanding of common Web Application and API vulnerabilities, including the OWASP Top 10 and OWASP API Security Top 10
Experience with penetration testing tools such as Burp Suite, Nmap, Metasploit, Nessus or equivalent
Experience with scripting and automation using Python, Bash, PowerShell or similar languages
Knowledge of penetration testing methodologies and frameworks, such as OWASP WSTG and PTES
Understanding of security technologies such as firewalls, IDS/IPS, WAFs and VPNs
Ability to prepare clear technical reports and communicate security findings to technical and business stakeholders
Excellent knowledge of the English language (written and verbal)
Flexibility to travel abroad, mainly EU countries, approximately 5% of working time
Relevant certifications such as OSCP, CEH, CPTS, PNPT, eCPPT, eWPT, CREST, GPEN, GWAPT, BSCP or CRTO are considered an asset, not required
Experience in Red Team operations, Mobile Application Penetration Testing or Social Engineering assessments is an asset
Experience in cloud security assessments, particularly Microsoft Azure or AWS, is an asset
Master's Degree in Information Security or a related discipline is an asset, not required

Benefits

Comp & perks

People-first approach and open environment to express your ideas
Work-life balance and a hybrid work model
Continuous training and development
Opportunities to join innovation initiatives
Ticket restaurant – meal vouchers
Corporate laptop and equipment
Corporate mobile phone subscription
Health and insurance plan for you and your family members
Employee consulting and guidance support by Ergonomia
Discounts on the services and products of our Group’s companies
Gift vouchers for major life milestones
Special work schedule on summer Fridays and birthdays
Equal employment opportunities and protection from discrimination