Senior Systems & Security Administrator

The Phoenix Group; New York (NY); On-site; USD 120,000 - 180,000; Full time

Job summary

The Phoenix Group is seeking a Senior Systems & Security Administrator to influence enterprise security architecture and operations within a growing legal and consulting environment. You will own critical security controls, system administration, automation, and incident response across cloud and on‑premises assets.

Collaborating with executives and technical teams, you will enhance security posture, resilience, and compliance, including ISO/IEC 27001 and related frameworks, while guiding

Qualifications

• 7+ years of systems administration experience, with at least 3 years in a senior role.
• Experience within formal security or compliance programs (ISO/IEC 27001, SOC 2, NIST CSF, HIPAA).
• Relevant certifications such as CISSP, CISM, GIAC, or Microsoft SC‑100/SC‑300.

Responsibilities

• Manage cloud and on‑prem infrastructure across multiple office locations.
• Administer Entra ID IAM with lifecycle, conditional access, MFA, and SSO.
• Oversee Microsoft 365 security, compliance, and endpoint management via Intune.
• Maintain enterprise network infrastructure including firewall, VPN, VLANs.
• Lead incident response, containment, eradication, and recovery efforts.
• Drive patching, vulnerability management, and follow‑up remediation.
• Develop change management procedures and system hardening standards.
• Maintain backup and disaster recovery tests and restores.
• Document runbooks, configurations, and audit evidence.

Job description

This position offers an opportunity to influence enterprise security architecture and operational excellence within a growing legal and consulting environment, ensuring robust protection of information assets while supporting operational continuity and compliance standards. The Senior Systems & Security Administrator will own critical security controls, system administration, automation, and incident response processes, collaborating closely with executive leadership and technical teams to enhance security posture and system resilience.

Key Responsibilities

• Manage and support the firm's cloud-based and on-premises infrastructure, including endpoints, network devices, and security controls, across multiple office locations.
• Administer identity and access management systems, including Microsoft Entra ID, with responsibilities for lifecycle management, conditional access, MFA, privileged access, and SSO.
• Oversee administration of Microsoft 365 suite (Exchange Online, SharePoint, OneDrive, Teams, Purview), including configuration, security, compliance, and endpoint management via Intune and Autopatch.
• Maintain and support enterprise network infrastructure, including firewall policies, VLAN segmentation, wireless networks, VPN, and web security platforms.
• Operate and monitor endpoint security tools such as EDR solutions (SentinelOne, Microsoft Defender) and DLP systems, triaging alerts and coordinating with Managed Security Operations Centers (SOC).
• Lead incident response efforts, including containment, eradication, and recovery activities, participating in root cause analysis and supporting the security incident response team.
• Manage vulnerability assessments, patching processes, and remediation activities across endpoints, servers, and network hardware; facilitate penetration testing and follow-up remediations.
• Develop, document, and implement change management procedures for configuration updates, system hardening standards, and firmware/software updates.
• Maintain backup and disaster recovery systems, executing restores, testing recovery procedures, and participating in business continuity exercises.
• Oversee asset and media management, including hardware inventory, licensing, and media disposition aligned with security and retention policies.
• Serve as encryption and cryptographic key custodian, ensuring secure handling and operational availability of cryptographic assets.
• Support compliance and audit preparations by gathering evidence, supporting ISO/IEC 27001 certification efforts, and addressing client security assessments.
• Collaborate on automation initiatives using PowerShell, Microsoft Graph, Intune, and platform-native workflows to streamline provisioning, configuration, reporting, and maintenance tasks, documenting all automation processes for team support.
• Manage and secure AI platforms, applying identity and data protections, while advising on responsible AI use and new capability evaluations.
• Develop and update technical documentation, procedures, runbooks, and system configurations to ensure operational continuity and compliance.

Core Qualifications & Requirements

• Minimum of 7 years of systems administration experience, with at least 3 years in a senior role managing production environments.
• Demonstrated experience within a formal security or compliance program, including ISO/IEC 27001, SOC 2, NIST CSF, HIPAA, or similar frameworks.
• Current or relevant certifications such as CISSP, CISM, GIAC, Microsoft SC-100, SC-300, or MD-102 are preferred.
• Deep technical knowledge of Microsoft cloud services (Entra ID, Exchange Online, SharePoint Online, Intune, Defender), enterprise network infrastructure (firewall, VPN, VLAN), and endpoint security operations.
• Expert-level scripting and automation skills with PowerShell, Microsoft Graph, and related tooling.
• Strong documentation practices in maintaining change logs, runbooks, configuration baselines, and audit evidence.
• Excellent communication skills, capable of explaining complex technical issues clearly to non-technical stakeholders.
• Sound judgment in handling privileged access, with an understanding of separation-of-duties policies.
• Commitment to confidentiality and data privacy aligned with organizational policies.
• Self-motivated, proactive, and resourceful with a collaborative team approach.
• Ability to prioritize tasks under pressure and adapt to changing circumstances, including after-hours support when needed.

Nice-to-Have Qualifications

• Experience supporting legal, regulatory, or compliance-related IT environments.
• Familiarity with automation platforms and cloud-native workflows beyond core scripting languages.
• Knowledge of AI platform management and responsible AI principles.

Core Technical Skills

• Cloud Infrastructure: Microsoft Entra ID (Conditional Access, MFA, SSO), Microsoft 365 Suite (Exchange, SharePoint, Teams, Purview), Intune, Autopatch
• Network: Cisco Meraki, Firewall management, VPN, VLAN segmentation, Web security platforms
• Security Operations: SentinelOne EDR, Microsoft Defender, Data Loss Prevention (DLP), Security Incident & Event Management (SIEM) support
• Scripting & Automation: PowerShell, Microsoft Graph, Intune Automation, native platform workflows
• Backup & Recovery: System Backup Configuration, Disaster Recovery, System Restorations
• Cryptography: Encryption key management and custody

This role offers a unique opportunity to shape and advance an enterprise security program within a mission-driven organization committed to public interest and social justice, ensuring the protection and resilience of critical legal and organizational assets.