Principal Penetration Tester - Mobile Application (f/m/x)

Our requirements

• Minimum 5 years of hands-on penetration testing experience, with a strong focus on mobile application security
• Practical experience testing iOS and Android applications, including common mobile attack paths and platform-specific risks
• Strong expertise in mobile security plus at least one additional domain: web applications or infrastructure
• Solid understanding of common vulnerabilities, attack techniques, and application security principles
• Strong grasp of TCP/IP fundamentals and network security concepts
• Confident using both manual and automated testing techniques
• Ability to explain complex technical issues to non-technical audiences clearly and calmly
• Strong analytical thinking and problem-solving skills
• Experience with scripting or programming languages
• Knowledge of OWASP mobile standards such as MASVS and MSTG
• Advanced level of English

Optional

• Experience in/or ability to run and deliver tests using the Corellium platform
• Ability to operate within a secure mobile testing environment, including access to appropriate test devices and tooling, in line with client and organizational security requirements
• Previous work with SAST, DAST, and IAST tools
• Familiarity with modern architectures, including microservices, APIs, and cloud environments
• Code review experience in Java, Kotlin, Swift, or Objective-C
• Knowledge of authentication and security mechanisms like OAuth2, JWT, biometrics, and SSL pinning
• Background in software development or secure SDLC
• Experience in financial services or other regulated environments

Your responsibilities

• Leading end-to-end mobile application penetration tests, including scoping, planning, execution, and reporting
• Delivering clear, high-quality outputs with practical remediation guidance and well-articulated risk assessments
• Acting as the go-to escalation point for complex technical challenges and high-impact findings
• Setting and evolving mobile testing methodologies, playbooks, and quality standards across the team
• Partnering with global penetration testing leads to aligning ways of working and sharing insights across regions
• Contributing to the improvement of frameworks, tooling, automation, and best practices with a strong focus on mobile security
• Building and maintaining an internal knowledge base of findings, trends, and lessons learned
• Supporting the vulnerability management lifecycle, including tracking, remediation, and risk acceptance
• Assisting in incident response and security investigations when needed
• Staying ahead of emerging attack vectors, tools, and techniques, especially in the mobile space

About the project

What we offer

• Great Place to Work since 2015 - it’s thanks to feedback from our workers that we get this special title and constantly implement new ideas
• Employment stability - revenue of PLN 2.1BN, no debts, since 2006 on the market
• We share the profit with Workers - over PLN 76M has already been allocated for this aim since 2022
• Attractive benefits package - private healthcare, benefits cafeteria platform, car discounts and more
• Comfortable workplace – class A offices or remote work
• Dozens of fascinating projects for prestigious brands from all over the world – you can change them thanks to Job Changer application
• PLN 1 000 000 per year for your ideas - with this amount, we support the passions and voluntary actions of our workers
• Investment in your growth – meetups, webinars, training platform and technology blog – you choose
• Fantastic atmosphere created by all Sii Power People

Recruitment stages

• 1.
  Send your CV
• 2.
  Talk to us about your expectations
• 3.
  Learn more about our projects and choose the best
• 4.
  Start your adventure with Sii!

Sii Sp. z o.o.