IT MANAGER/SENIOR SYSTEMS ADMINISTRATOR

3Core Systems , Inc•Littleton, CO

2d•Onsite

About The Position

The IT Manager/Senior Systems Administrator will lead the administration of various IT infrastructure components, including identity and access governance, file and storage services, email and collaboration platforms, server and virtualization infrastructure, network and perimeter security, security operations, eDiscovery, telephony, and automation. This role involves hands-on management of Windows Server, Active Directory, Microsoft 365, VMware vSphere, and network security devices. The position also requires managing software licenses, coordinating technical projects, overseeing change management, ensuring IT security and policy compliance, and providing technical leadership and escalation. Additionally, the role involves monitoring and coordinating critical-environment infrastructure like power and cooling systems.

Requirements

In-depth knowledge of Microsoft Windows Server, Active Directory, Microsoft 365, MS Teams, and Multi-Factor Authentication.
Hands-on experience administering non-human identity: service accounts, service principal names, Entra ID app registrations, and credential lifecycle management.
Experience with VMware vSphere virtualization.
Strong experience administering Windows file servers and network storage at scale - permissions, quotas, capacity monitoring, and migrations.
Strong understanding of email flow and mail security, including routing, spam, malware, and DLP; hands-on experience with a secure email gateway (Proofpoint, Mimecast, or similar).
Strong understanding of networking concepts and protocols (TCP/IP, DNS, DHCP, VLANs, etc.), coupled with experience in configuring, monitoring, and managing firewalls to secure the corporate network, and enforce access controls.
Experience with endpoint protection and data-governance platforms (CrowdStrike, Varonis, or similar).
Proficiency with PowerShell for infrastructure automation, reporting, and administration.
Hands-on experience with physical server hardware, including racking, structured cabling, hardware diagnostics, and component replacement (disks, memory, power supplies, etc.).
Working knowledge of the power and environmental requirements of server rooms and network closets, including UPS systems, rack PDUs, electrical capacity, cooling, temperature/humidity monitoring, and escalation to facilities, datacenter, and building vendors.
Proven experience as a Systems Administrator or similar role, with 7+ years managing enterprise IT infrastructure in a hands-on environment.
Experience supporting DR, backup/restore testing, infrastructure monitoring, change control, and documented operational procedures.
Experience operating and evidencing IT controls in a regulated or audited environment, including access reviews, change management, exception management, and policy compliance.
Demonstrated experience with software and cloud-license governance, entitlement reviews, vendor renewals, and cost-conscious subscription management.
Proven ability to lead technical projects and coordinate internal stakeholders, managed service providers, and other vendors from scope through implementation.
Strong organizational skills, with the judgment to identify control gaps, document risks, drive remediation, and communicate status clearly to technical and non-technical stakeholders.
Excellent problem-solving skills and attention to detail.
Strong communication and interpersonal skills, including the ability to explain technical issues to non-technical stakeholders.
Discretion and sound judgment when handling confidential company, employee, and legal data.
A practical, service-oriented approach; able to balance competing priorities, document work clearly, and escalate risks appropriately.
Comfortable serving as a technical escalation point and mentoring junior IT staff.

Nice To Haves

Bachelor's degree in Computer Science, Information Technology, or related field (or equivalent experience).
Experience in financial services or another regulated, audited environment.
Exposure to eDiscovery, legal hold, or regulatory production processes.
Experience with cloud computing platforms such as AWS or Azure is a plus.
Experience with configuration management tooling (Ansible, PowerShell DSC, or similar) is beneficial.
Familiarity with market data platforms, particularly Bloomberg administration and entitlements.
Familiarity with Avaya PBX administration, analog/POTS lines, and telecom vendor coordination.

Responsibilities

Lead the administration of Active Directory architecture, group design, and service-account estate (service principal names, Entra ID application registrations, Graph API access, credential rotation).
Maintain access standards, run periodic access and service-account reviews, and process access exceptions.
Administer Windows and Samba file-server estate, manage capacity, quotas, monitoring, and oversee archiving, backup, and data-governance tooling.
Administer Microsoft 365 and Exchange Online, including mail routing, security, DLP, retention, journaling, and the Teams, SharePoint, and OneDrive estate.
Build, patch, and maintain the Windows Server estate on VMware vSphere, including hands-on work with physical server hardware.
Administer and troubleshoot TCP/IP, DNS, DHCP, VLANs, wireless networks, certificates, and infrastructure-monitoring platforms.
Configure, monitor, and manage firewalls to enforce access controls and protect the corporate network.
Manage telecom and ISP vendor relationships.
Administer endpoint protection, data-governance, and email-security platforms.
Manage multi-factor authentication, conditional access, and geographic access restrictions.
Run the security-awareness and phishing-simulation program.
Respond to security alerts and vulnerabilities.
Perform mailbox and file searches for eDiscovery and legal hold purposes, preserving, collecting, and producing data confidentially.
Support the current Avaya PBX, associated analog lines, and voice-service vendors.
Troubleshoot and coordinate resolution of telephony incidents, provisioning, and office moves.
Assist with the planned transition of PBX operations to an outsourced provider and oversee the vendor relationship.
Use PowerShell and Python to automate provisioning, reporting, and task scheduling.
Maintain our enterprise job scheduling platform.
Oversee software and cloud-service entitlements, licensing, renewals, procurement, and vendor relationships.
Review user licensing and assignments across various platforms.
Recommend and implement subscription changes to align user access, device management, security, and operational needs.
Own the technical delivery of infrastructure and security projects from requirements gathering to acceptance and documentation.
Define and maintain project plans, timelines, dependencies, risks, and action items.
Track project progress, escalate issues, and coordinate stakeholders.
Maintain accurate records of infrastructure, configuration, and access changes.
Perform monthly reviews of Active Directory group membership, workstation configuration, local administrator access, server assignments, and system usage.
Investigate and remediate discrepancies in IT controls.
Document findings, approvals, exceptions, and follow-up actions.
Maintain operational controls supporting IT policies, client and regulatory due-diligence questionnaires (DDQs), and external security representations.
Ensure alignment between documented policies, DDQ responses, and day-to-day practices.
Monitor and validate controls for password rotation, service accounts, least-privilege access, patching, and exception management.
Route and prioritize support tickets, coordinate support coverage and issue resolution.
Serve as the technical escalation point for IT support staff.
Mentor junior team members and promote clear documentation, consistent operational practices, and timely risk escalation.
Monitor and coordinate power, cooling, and environmental systems supporting office technology rooms and server rooms.
Coordinate with building management, datacenter providers, electricians, and HVAC vendors during incidents and maintenance.