Senior Systems Administrator

Key Responsibilities: Manage Active Directory, Entra ID, service accounts, MFA, access reviews, and security controls. Administer Microsoft 365, Exchange Online, Teams, SharePoint, OneDrive, email security, and DLP.Manage Windows Server, VMware vSphere, file servers, storage, backups, and migrations. Administer networks, DNS, DHCP, VLANs, wireless, certificates, firewalls, and telecom. Manage endpoint security, vulnerabilities, phishing simulations, and data-governance tools. Support eDiscovery, legal holds, audits, regulatory requests, and IT controls. Automate administration and reporting using PowerShell and Python. Manage software/cloud licensing, vendors, renewals, and procurement. Lead infrastructure and security projects from planning through implementation. Maintain change management, documentation, compliance, and operational procedures. Serve as technical escalation point and mentor junior IT staff. Coordinate server-room power, cooling, UPS, and datacenter infrastructure.

Required Qualifications: 7+ years of hands-on enterprise systems administration experience. Strong Windows Server, Active Directory, Microsoft 365, MFA, and PowerShell skills. Experience with Entra ID, service accounts, application registrations, and credential management. Strong VMware, storage, networking, firewall, and email-security experience. Experience with security tools such as CrowdStrike, Varonis, Proofpoint, or similar. Experience with backups, DR, monitoring, change control, and regulated/audited environments. Strong project, vendor-management, documentation, and communication skills.

Preferred: Bachelor's degree or equivalent experience. Financial services or regulated-industry experience. AWS/Azure, Ansible, eDiscovery, Bloomberg, or Avaya experience.

Working Conditions: Fully on-site; no remote/hybrid option. Occasional after-hours maintenance and recovery work. NYC employees may travel to CT/Westchester DR facilities.