Principal Security Engineer – AI & Copilot Data Protection

About Northern Trust: Northern Trust, a Fortune 500 company, is a globally recognized, award-winning financial institution that has been in continuous operation since 1889. Northern Trust is proud to provide innovative financial services and guidance to the world’s most successful individuals, families, and institutions by remaining true to our enduring principles of service, expertise, and integrity. With more than 130 years of financial experience and over 22,000 partners, we serve the world’s most sophisticated clients using leading technology and exceptional service. Role Summary Seeking a Principal‑level individual contributor to lead the secure enablement of Microsoft 365 Copilot and enterprise AI capabilities within Northern Trust's Cyber Team. This role owns the end‑to‑end technical strategy, architecture, and operationalization of AI‑driven data protection and compliance controls across Microsoft Purview, Defender, and M365 security services. The Principal serves as the organization’s deep technical authority on AI data protection, shaping control strategy, influencing platform configuration decisions, and institutionalizing durable safeguards that reduce AI‑driven data risk while enabling productivity at enterprise scale. This is a hands‑on role with architect‑level accountability: designing systems that will stand up to audit, regulatory scrutiny, and adversar [... source excerpt omitted ...] ore incidents occur, translating emerging AI threats into preventive controls. Serve as escalation point and design authority for complex or ambiguous AI security decisions. Key Responsibilities AI & Copilot Security Architecture Act as hands‑on technical lead and design authority for Copilot and enterprise AI security controls across Microsoft Purview, Defender, and M365. Define and evolve the AI data protection reference architecture, mapping controls to AI threat models and regulatory expectations. Review and harden Copilot platform configurations, including: Web grounding and search behaviors Agents, plugins, and connectors Permission inheritance and identity context Tra [... source excerpt omitted ...] orcement DSPM for AI, including exposure detection and oversharing remediation Configure, deploy, troubleshoot, and operate controls across AD and EntraID environments. Support production changes through disciplined change management and approved deployment windows. AI Risk Detection, Monitoring & Response Define AI‑specific risk use cases, signals, and thresholds aligned to data exposure, misuse, and policy violation scenarios. Build monitoring, alerting, and automation for abnormal or high‑risk AI usage patterns. Develop operational runbooks that enable consistent response, investigation, and evidence preservation. Ensure solutions are audit‑ready, regulator‑defensible, a