Penetration Tester

We are seeking a Penetration Tester to join the M365 Core team, specifically within the Substrate organization. As a Penetration Testing Specialist, you will have the opportunity to work on global scale services, performing research and offensive security operations against M365 backed infrastructure.

Responsibilities:

• Vulnerability Discovery & Exploitation: Find and validate security vulnerabilities through hands-on penetration testing, code review, and proof-of-concept exploit development.
• Tooling & Automation: Build and maintain automated and autonomous tooling to scale offensive security testing and vulnerability discovery.
• Research & Threat Analysis: Investigate emerging attack techniques, exploit classes, and AI/agentic system threats.
• Security Architecture Collaboration: Work with Security Architecture and service teams to assess design-level risks, review threat models, and inform platform hardening based on offensive findings.
• Reporting & Remediation: Write technical reports that clearly describe what's broken, the impact, and how to fix it.
• Detection & Blue Team Partnership: Work with detection engineering and blue teams to validate coverage and close detection gaps from offensive findings.

Qualifications:

• Bachelor's Degree in Statistics, Mathematics, Computer Science or related field OR 3+ years experience in software development lifecycle, large-scale computing, modeling, cybersecurity, and/or anomaly detection.
• 3+ years of experience in security research, penetration testing, or offensive security roles.
• Hands-on experience discovering and exploiting vulnerabilities in AI systems and platforms.
• Proficiency in Python with experience in AI frameworks and security testing tools.
• Ability to read and analyze code across multiple languages and codebases.