Principal Security Engineer

Microsoft's Cloud & AI organization develops security capabilities to protect digital platforms, devices, clouds, and internal environments. The Principal Security Engineer will lead end-to-end CyberShield adversary emulation operations, direct AI-driven red team agents, develop offensive tooling, engage customer security leaders, and improve defender readiness.

Responsibilities:

• Execute CyberShield red team operations end-to-end – initial access, privilege escalation, lateral movement and pivoting, persistence, objective completion, and reporting – against Microsoft's own environment and select external customer environments, using real-world adversary tactics, techniques, and procedures to validate detection, investigation, and response
• Develop custom tooling, implants, and tradecraft to evade modern defenses and emulate the capabilities of advanced adversaries
• Lead agentic red team operations: design and direct AI agents that autonomously perform reconnaissance, vulnerability discovery, exploitation, and post-exploitation; define guardrails, oversight, and human-in-the-loop checkpoints; and drive the shift from human-led execution to continuous, software-driven, agentic analysis
• Discover and exploit vulnerabilities end-to-end across application, cloud, identity, network, hardware, and operational security layers, chaining findings into realistic attack paths that demonstrate business impact
• Serve as the forward-deployed technical lead with customers: brief CISOs and security leaders, translate findings into actionable narratives, and deliver lightweight defensive engineering guidance alongside offensive results
• Prototype and productionize tools, agents, and techniques that scale offensive emulation and vulnerability discovery, and feed requirements back to our offensive AI platform engineering team based on what works in real environments
• Collaborate with Blue Teams, GHOST (Microsoft's adversary hunting organization, which proactively hunts for and responds to real-world intrusions in Microsoft and customer environments), MSTIC (the Microsoft Threat Intelligence Center, which tracks nation-state and criminal threat actors and their tradecraft), and internal Microsoft service teams to convert findings into product hardening and improved defender readiness
• Set operational standards and playbooks for CyberShield engagements; mentor senior operators and virtual-team specialists drawn from across MRT
• Advocate for security change across Microsoft and its customers by building partnerships and clearly communicating the impact of risk
• Embody our Culture and Values

Requirements:

• Master's Degree in Statistics, Mathematics, Computer Science, or related field AND 6+ years experience in security or related field OR Bachelor's Degree in Statistics, Mathematics, Computer Science, or related field AND 8+ years experience in security or related field OR equivalent experience
• Ability to meet Microsoft, customer and/or government security screening requirements are required for this role
• Master's Degree in Statistics, Mathematics, Computer Science, or related field AND 8+ years experience in security or related field OR Bachelor's Degree in Statistics, Mathematics, Computer Science, or related field AND 12+ years experience in security or related field OR equivalent experience
• 6+ years of experience planning and leading red team or adversary emulation operations against enterprise or cloud environments
• Demonstrated hands-on experience building, directing, or operating AI-driven or agentic offensive security tooling in real operations
• 8+ years of experience identifying and exploiting security vulnerabilities across cloud (Azure, AWS, GCP), identity (Entra ID / Active Directory), Windows and Linux endpoints, network, and hardware
• Experience designing multi-agent or autonomous systems using large language models – orchestration frameworks, tool use, agent evaluation, and safety guardrails – applied to offensive security
• 6+ years of experience with coding or scripting in languages such as Python, C#, C++, Go, PowerShell, .NET, Rust, or other comparable programming languages, including building and maintaining offensive tooling
• Experience in customer-facing or consulting roles delivering red team results to executive audiences; ability to move fluently between deep technical detail and business impact
• Blue team, detection engineering, or incident response experience – you understand how defenders think and can help them get better
• Familiarity with MITRE ATT&CK, threat-informed defense, and regulated red team frameworks (e.g., TIBER-EU, CBEST, DORA)
• Recognized contributions to the security community: research, open-source tooling, conference talks, or CVEs
• Active U.S. Government TS//SCI clearance with full-scope polygraph is a strong plus, enabling immediate work with our most sensitive customers