Application Security Penetration Tester - Web, Mobile & API

Our client, a leading global financial services organisation, is looking for an experienced Application Security Penetration Tester to join a growing Application Security team based in Letterkenny. This is an excellent opportunity to work on large-scale, business-critical applications while partnering with development teams to improve the security posture of enterprise platforms.

This role is ideal for a penetration tester with strong experience in manual web, mobile and API security testing who enjoys working closely with technical stakeholders and providing practical remediation guidance.

About the Opportunity

As an Application Security Penetration Tester, you will be responsible for delivering high-quality security assessments across a broad portfolio of applications. You'll work with modern technologies, identify vulnerabilities through manual testing, and help development teams understand and remediate security risks.

You'll be joining a collaborative security function that values technical excellence, continuous learning, and innovation.

Key Responsibilities

• Perform manual penetration testing of web applications, mobile applications (iOS & Android), and REST/SOAP APIs.
• Scope penetration testing engagements by working with stakeholders to understand application functionality and testing requirements.
• Identify, validate, and exploit application vulnerabilities using recognised industry methodologies.
• Produce clear, evidence-based penetration testing reports with risk ratings and practical remediation recommendations.
• Present findings to technical and non-technical stakeholders and provide guidance throughout the remediation process.
• Conduct remediation verification and retesting to confirm vulnerabilities have been successfully resolved.
• Collaborate with development, engineering, and security teams to improve secure development practices.
• Research emerging application security threats, vulnerabilities, and attack techniques to continuously enhance testing approaches.
• Contribute ideas and improvements to penetration testing methodologies, tooling, and processes.

Required Skills & Experience

• 4 + years' experience in Application Security Penetration Testing.
• Strong hands-on experience performing manual testing of web applications, mobile applications, and APIs.
• Solid knowledge of the OWASP Web Security Testing Guide (WSTG) and common web application vulnerabilities.
• Experience assessing and prioritising vulnerabilities using CVSS.
• Proficiency with security testing tools including Burp Suite Professional, DAST scanners, Jira, and ServiceNow.
• Excellent report writing skills with the ability to communicate technical findings clearly and provide actionable remediation advice.
• Strong stakeholder management and communication skills, with experience engaging both technical and business audiences.
• Ability to manage multiple penetration testing engagements while maintaining a high standard of delivery.

Desirable Experience

• Mobile application penetration testing across iOS and Android.
• Professional certifications such as OSCP, Burp Suite Certified Practitioner (BSCP), or HTB CPTS.
• Experience testing AI-enabled applications, including chatbots and LLM-based solutions, using emerging OWASP AI testing guidance.
• Network or infrastructure penetration testing experience.
• Software development or secure coding experience.
• Experience working within financial services or another highly regulated industry.

What's on Offer

• Opportunity to work on complex, enterprise-scale applications within a mature security environment.
• Exposure to modern application security technologies and methodologies.
• Career development and support for ongoing technical learning and professional certifications.
• Competitive salary and comprehensive benefits package. Permanent role with a hybrid working model.

Salary dependent on candidate experience. Benefits: Annual Bonus Scheme. Contributory Pension. Private Medical Insurance. Life Assurance & Long-Term Disability. Employee Assistance Programme. 22 days annual leave + 10 public holidays. Relocation package. Continuous Learning & Development. Access to extensive training & certification resources. Lunch & Learn sessions. Additional perks including company discounts, on-site parking, and bike-to-work scheme

Based in Letterkenny, Co. Donegal. Hybrid (2 days onsite per week). Candidates must be eligible to work in Ireland/EU.

For more information, please contact David Coyle at 01 635 1748 or email [email protected]