Senior IT Systems Administrator (On-Site) with Security Clearance

Information Technology$146k/yrFull-time

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:

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:

Administer and optimize UniFi / 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:

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:

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.

5+ years of progressively responsible, hands-on IT systems administration experience; 7+ years preferred.
Demonstrated success operating as a senior administrator, lead systems resource, or primary IT owner in a Windows-centric environment.
Strong hands-on experience with:

Experience with Ubiquiti / UniFi networking equipment and administration.
Experience designing or improving endpoint lifecycle processes, including deployment, provisioning, inventory tracking, software management, patching, and redeployment.
Experience with on-prem infrastructure, server administration, virtualization/hypervisors, backup practices, and infrastructure consolidation planning.
Working knowledge of Linux server administration in a mixed Windows/Linux environment.
Experience implementing security hardening and configuration baselines; STIG experience is required.
Strong troubleshooting, communication, documentation, and prioritization skills.
Ability to work independently, take ownership, and build structure in an environment that is being matured and standardized.
Ability to pass a background check.
Must be able to work 100% on-site in Rockville, MD 20852.

Experience with Azure migration planning, hybrid identity, and directory synchronization troubleshooting.
Experience with Microsoft-native endpoint/security tooling such as:

Familiarity with CMMC Level 2, NIST 800-171, or similar security/compliance frameworks.
Experience supporting small-to-mid-sized organizations where the administrator is expected to combine strategy, execution, documentation, and operational ownership.
Relevant certifications such as:

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