Senior IT Systems Administrator; On-Site Security Clearance

Position: Senior IT Systems Administrator (On-Site) with Security Clearance
Date posted:
March 26, 2026 Pay: $ - $ per year

Job description:

Senior IT Systems Administrator (On-Site)
Strategic Technology Institute, Inc. (STi)

Location:

Rockville, MD 20852
Job Type: Full-time

Work Schedule:

Standard business hours, Monday-Friday
Work Arrangement: 100% on-site at STi Headquarters

Position Overview Strategic Technology Institute, Inc. (STi) is seeking a hands-on Senior IT Systems Administrator to serve as the primary on-site owner of IT infrastructure and systems administration for our Headquarters in Rockville, Maryland. This is a role for a mid-level to senior professional who is equally comfortable assessing the current environment, creating a practical roadmap, recommending improvements to leadership, and personally executing the work.

The right person will help us mature and standardize our IT environment, strengthen security, modernize endpoint and identity management, improve network performance, and establish repeatable processes for device lifecycle management, user support, and infrastructure administration. Our environment is primarily Windows-based, with Microsoft 365, Teams Phone, SharePoint, Active Directory, Azure / Microsoft Entra , Windows desktops and laptops, some Linux-based servers, on-premises infrastructure, and a current hybrid on-prem / Azure setup that we want to evaluate and improve.

We are looking for someone who wants to take ownership, build structure, and help improve our environment over the long term. This is not a remote or hybrid role.

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- Key Responsibilities Serve as the primary on-site IT systems administrator and senior technical resource for STi Headquarters.
Assess, document, and improve the organization’s existing IT architecture, systems administration practices, security posture, and operational processes.
Administer and improve the Microsoft environment, including:
Microsoft 365
Active Directory
Azure / Microsoft Entra
Group Policy
Intune
SharePoint Online
Teams Phone
Windows desktops and laptops
Evaluate the current hybrid on-prem / Azure environment, troubleshoot identity and synchronization issues, and recommend whether STi should remain hybrid or move further toward Azure.
Lead management of network infrastructure and security, including:
firewall administration
VLANs and subnetting
switching and routing
wireless networking
traffic segmentation
performance troubleshooting
network documentation
Administer and optimize Uni Fi / Ubiquiti networking hardware and software.
Design and implement a dedicated VoIP subnet and apply appropriate QoS policies to improve voice quality, reliability, and throughput.
Evaluate current on-prem infrastructure, including server rack assets, hosted services, virtualization/hypervisor footprint, and mixed Windows/Linux server workloads; recommend and execute consolidation, retirement, or migration where appropriate.
Administer and support both Windows and Linux servers, including patching, monitoring, backup coordination, access controls, and ongoing maintenance.
Establish a standardized, repeatable process for new laptop deployment, device provisioning, imaging/enrollment, software installation, asset tracking, user handoff, device return, reissue, and retirement.
Replace ad hoc manual laptop turnover practices with a secure, supportable lifecycle process that includes:
device intake/check-in
backup/transfer standards
wipe/redeployment procedures
baseline configuration
readiness for office and field users
Enroll and manage organizational devices in Microsoft Intune and implement standardized controls for:
device enrollment
compliance policies
configuration profiles
software deployment
updates/patching
remote management
baseline enforcement
Implement and maintain Group Policy, standardized endpoint configurations, hardening baselines, and software control processes.
Apply and maintain STIG-aligned security baselines and help improve the office environment’s overall security maturity.
Support long-term alignment toward stronger security and compliance practices, including awareness of CMMC Level 2-style controls, even where not currently required in the headquarters environment.
Support and administer SharePoint Online for file storage, collaboration, permissions, and operational workflows.
Provide senior-level troubleshooting and escalation support across desktop, server, Microsoft 365, identity, network, and endpoint issues.
Maintain accurate and current:
network diagrams
asset inventories
system documentation
standard operating procedures
deployment procedures
configuration records
recovery documentation
Mentor and guide junior or entry-level support personnel performing basic IT tasks, helping build internal capability and consistency.
Serve as a trusted internal partner who can identify issues, prioritize them appropriately, and drive practical solutions that improve reliability, security, and maintainability.

Required Qualifications 5+ years of progressively responsible,…