Senior System Administrator
First seen by Alion on Oct 6, 2026.
JOB PURPOSE
We are seeking an experienced Senior System Administrator with strong technical expertise and leadership capabilities to manage and maintain our enterprise IT infrastructure. In this role, you will oversee Windows Server Domain environments, Microsoft Exchange, Hyper-V virtualization, and Fortinet/FortiGate network security infrastructure. Additionally, you will lead, mentor, and direct the technical support team to ensure high availability, security, and seamless daily operational support across the organization.
Duties and Tasks:
1. Infrastructure & Server Administration
Design, deploy, configure, and maintain Microsoft Windows Server infrastructure (Active Directory, DNS, DHCP, Group Policy/GPO, and ADFS).
Manage and maintain Microsoft Exchange Server environments, ensuring email deliverability, mailbox database management, hygiene (SPF/DKIM/DMARC), and disaster recovery preparedness.
Administer, optimize, and manage Hyper-V virtualized environments, including failover clustering, virtual machine allocation, host resource management, and high-availability setups.
Perform routine system updates, patch management, and hardware firmware maintenance across physical and virtual hosts.
2. Network Security & Firewall Operations
Configure, manage, and monitor FortiGate Next-Generation Firewalls (NGFW).
Implement and maintain security policies, site-to-site VPNs, SSL-VPN remote access, IPS/IDS, Web Filtering, and Application Control.
Monitor network traffic, performance, and security logs to detect, prevent, and remediate unauthorized access or network incidents.
3. Team Leadership & IT Support Management
Lead, schedule, and supervise the Tier 1 / Tier 2 technical support team to ensure prompt resolution of user issues and adherence to SLAs.
Act as the senior escalation point for complex technical issues, hardware failures, and network outages.
Establish standard operating procedures (SOPs), ticketing workflows, and clear technical documentation for the IT support team.
Conduct performance evaluations, technical mentoring, and skill-development plans for support personnel.
4. Backup, Security & Disaster Recovery
Manage backup solutions (e.g., Veeam, enterprise cloud backups) to ensure reliable host, database, and VM restoration points.
Implement cybersecurity best practices across domain controllers, servers, and endpoints in alignment with company policies.
Develop, test, and document Disaster Recovery (DR) and business continuity plans.
Requirements
Bachelor's Degree in Computer Science, Information Technology, or a related field.
Experience: Minimum of 5 years of hands-on experience in the same role (System Administrator / Senior Infrastructure Engineer).
Core Systems: Proven mastery of Windows Server (2016/2019/2022), Active Directory Domain Services, and Microsoft Exchange Server.
Virtualization: Deep technical experience managing Microsoft Hyper-V environments and Failover Clusters.
Network & Security: Strong administration expertise with FortiGate Firewalls, routing, switching, VLANs, and VPN protocols.
Leadership: Proven leadership or supervisory experience managing helpdesk/technical support engineers.
Strong analytical and troubleshooting skills under operational pressure.
Knowledge of cloud integration (Microsoft 365, Azure AD / Entra ID hybrid setups) is a plus.
Relevant professional certifications:
Microsoft: MCSA / MCSE or Microsoft Certified: Windows Server Hybrid Administrator Associate.
Fortinet: Fortinet Certified Associate (FCA) or Fortinet Certified Professional (FCP - Network Security / NSE 4).
Excellent analytical and problem-solving skills.
Ability to manage multiple tasks and priorities efficiently.
Ability to work under pressure and meet deadlines.
Good command of written and spoken English.