Senior Security Administrator

The Phoenix Group®; United States; Hybrid; USD 120,000 - 160,000; Full time

Job summary

The Phoenix Group® is seeking a hands-on Senior Systems & Security Administrator to own its infrastructure, security operations, and automation. You’ll work with leadership to strengthen security posture, keep systems resilient, and support compliance goals.

Responsibilities include managing hybrid environments, Entra ID, M365, Intune, Autopatch, patching, incident response, vulnerability management, backups, audits, and automation with PowerShell and Graph.

Qualifications

• 5+ years in systems administration, including senior level in production environments.
• Experience within formal compliance frameworks such as ISO 27001, SOC 2, NIST CSF, or HIPAA.
• Deep knowledge of Microsoft cloud stack, enterprise networking, and endpoint security.

Responsibilities

• Run the firm's hybrid environment (cloud and on premises) across offices, endpoints, network gear, and security tooling.
• Own identity and access in Entra ID: user lifecycle, MFA, conditional access, SSO, and privileged accounts.
• Administer Microsoft 365 (Exchange Online, SharePoint, OneDrive, Teams, Purview) and manage devices via Intune and Autopatch.
• Maintain firewalls, VLANs, wireless, VPN, and web filtering.
• Monitor EDR and DLP tools (SentinelOne, Defender), triage alerts, and coordinate with outsourced SOC.
• Lead incident response from containment through recovery, including root cause reviews.
• Drive vulnerability management, patching, and pen test remediation.
• Build and enforce change management, hardening standards, and update procedures.
• Manage backups and DR, including restore testing and business continuity exercises.
• Track hardware, licenses, and secure media disposal; custodianship of encryption keys.
• Support audits and ISO 27001 certification work.
• Automate routine tasks with PowerShell, Graph, and native workflows, document everything.

Skills

Cloud security

ISO 27001 / SOC 2 / NIST CSF

Microsoft 365 security

PowerShell / Graph scripting

Documentation & runbooks

Security incident response

Tools

Intune

Autopatch

SentinelOne

Defender

Job description

About The Role

We’re looking for a hands-on Senior Systems & Security Administrator to own its infrastructure, security operations, and automation. You'll work directly with leadership and technical staff to strengthen the firm's security posture, keep systems resilient, and support its compliance goals.

About The Role

We’re looking for a hands-on Senior Systems & Security Administrator to own its infrastructure, security operations, and automation. You'll work directly with leadership and technical staff to strengthen the firm's security posture, keep systems resilient, and support its compliance goals.

What You’ll Do

• Run the firm's hybrid environment (cloud and on premises) across several offices, covering endpoints, network gear, and security tooling.
• Own identity and access in Entra ID: user lifecycle, MFA, conditional access, SSO, and privileged accounts.
• Administer Microsoft 365 (Exchange Online, SharePoint, OneDrive, Teams, Purview) and manage devices through Intune and Autopatch.
• Maintain firewalls, VLANs, wireless, VPN, and web filtering.
• Monitor EDR and DLP tools (SentinelOne, Defender), triage alerts, and work alongside an outsourced SOC.
• Lead incident response from containment through recovery, including root cause reviews.
• Drive vulnerability management, patching, and pen test remediation.
• Build and enforce change management, hardening standards, and update procedures.
• Manage backups and DR, including restore testing and business continuity exercises.
• Track hardware, licenses, and secure media disposal; act as custodian for encryption keys.
• Support audits, client security questionnaires, and ISO 27001 certification work.
• Automate routine tasks with PowerShell, Microsoft Graph, and native platform workflows, and document everything so others can support it.
• Secure the firm's AI platforms and help guide responsible adoption of new AI tools.

What You Bring

• 5+ years in systems administration, including 3+ at a senior level in production environments.
• Experience working within a formal compliance framework such as ISO 27001, SOC 2, NIST CSF, or HIPAA.
• Deep knowledge of the Microsoft cloud stack, enterprise networking, and endpoint security.
• Advanced PowerShell and Graph scripting skills.
• Disciplined documentation habits: runbooks, change logs, baselines, and audit evidence.
• Certifications such as CISSP, CISM, GIAC, SC-100, SC-300, or MD-102 are a plus.