Senior Info Security Engineer

Based in St. Louis, Core & Main is a leader in advancing reliable infrastructure with local service, nationwide. As a specialty distributor with a focus on water, wastewater, storm drainage and fire protection products and related services, Core & Main provides solutions to municipalities, private water companies and professional contractors across municipal, non-residential and residential end markets, nationwide. With over 370 locations across the U.S., the company provides its customers local expertise backed by a national supply chain.

Core & Main's 5,700 associates are committed to helping their communities thrive with safe and reliable infrastructure. Visit to learn more.

We are seeking a Senior Information Security Engineer to strengthen enterprise security controls and improve operational effectiveness across security monitoring, cloud identity and access management, privileged access management, and support of SOC/MDR and threat intelligence functions.

This is a hands‑on senior engineering role responsible for designing, implementing, operating, and improving security capabilities in a complex enterprise environment. The role partners closely with security leadership and architecture to translate strategy into measurable engineering outcomes and serves as a senior technical resource for complex security engineering issues across core control domains.

• Own and enhance enterprise security monitoring capabilities across SIEM and related telemetry platforms.
• Design, implement, and improve detections, dashboards, alerting, and monitoring content to increase signal quality and operational value.
• Engineer reliable telemetry collection, normalization, and monitoring workflows to support data quality, operational resilience, and long‑term maintainability.
• Partner with SOC and MDR stakeholders to improve monitoring coverage, detection effectiveness, and response outcomes.
• Mature detection engineering practices, use cases, and workflows to strengthen monitoring quality over time.

• Design, implement, and support cloud IAM controls focused on least privilege, access governance, and identity‑based security.
• Build and maintain controls in platforms such as Microsoft Entra, including Conditional Access and privileged access controls.
• Strengthen identity posture across users, administrators, service principals, and other non‑human identities.
• Evaluate and improve access models to reduce risk while supporting business operations.

• Improve SOC and MDR effectiveness through enhancements to detection content, enrichment, workflows, and technical integrations.
• Collaborate with incident response, MDR, and threat intelligence stakeholders to strengthen threat‑informed monitoring and investigative value.
• Provide engineering support during security incident escalations, including troubleshooting, coordination, and improvement of detection and response workflows.
• Drive post‑incident improvements that increase visibility, prioritization, and operational effectiveness.

• Build, operate, and mature privileged access capabilities that protect privileged credentials, administrative access, and high‑risk workflows.
• Standardize and improve privileged account onboarding, credential governance, vaulting, rotation, and access workflows.
• Strengthen the reliability, auditability, and operational effectiveness of PAM services through clear runbooks and repeatable processes.
• Partner with security and infrastructure teams to ensure PAM capabilities are scalable and aligned to enterprise standards.

• Partner with security leadership and architecture to implement strategic security priorities through well‑engineered, measurable controls.
• Serve as a senior technical resource and escalation point for complex security engineering issues across core control domains.
• Contribute to security design reviews, technical standards, and implementation guidance for identity, monitoring, and privileged access domains.
• Create and maintain technical…