Senior System Administrator
First seen by Alion on Jul 22, 2026.
We are looking for an experienced Senior System Administrator to manage and maintain enterprise IT infrastructure, ensuring high availability, security, and performance across servers, virtualization platforms, cloud environments, storage, and network services.
The ideal candidate will have extensive experience in Windows and Linux administration, Active Directory, virtualization, cloud technologies, infrastructure automation, backup solutions, and enterprise security.
The role requires strong troubleshooting skills, infrastructure planning capabilities, and the ability to lead critical system administration initiatives while collaborating with cross-functional IT and security teams.
Key Responsibilities:
- Administer, configure, and maintain enterprise Windows and Linux server environments.
- Manage Active Directory, Group Policy Objects (GPO), DNS, DHCP, LDAP, and identity management services.
- Install, upgrade, patch, and troubleshoot Windows Server and Linux operating systems.
- Manage VMware vSphere, ESXi, vCenter, Hyper-V, and virtual infrastructure.
- Monitor server health, capacity planning, and infrastructure performance using enterprise monitoring tools.
- Implement and maintain high availability, clustering, load balancing, and disaster recovery solutions.
- Configure and manage enterprise storage solutions including SAN, NAS, and distributed storage environments.
- Perform backup, restoration, and disaster recovery using enterprise backup tools such as Veeam, Commvault, Veritas NetBackup, or Rubrik.
- Deploy, configure, and maintain cloud infrastructure on AWS, Azure, or Google Cloud Platform.
- Automate routine administration tasks using PowerShell, Bash, or Python.
- Manage Microsoft Exchange (On-Prem/Hybrid), Microsoft 365, and Azure Active Directory where applicable.
- Implement infrastructure security best practices including hardening, vulnerability remediation, patch management, and access control.
- Collaborate with network, database, cloud, DevOps, and cybersecurity teams to resolve complex infrastructure issues.
- Perform root cause analysis for critical incidents and implement preventive measures.
- Create infrastructure documentation, SOPs, architecture diagrams, and operational runbooks.
- Participate in infrastructure upgrades, migrations, datacenter projects, and cloud transformation initiatives.
- Mentor junior system administrators and provide technical guidance.
Required Skills:
- 812 years of experience in System Administration and Enterprise Infrastructure Management.
- Strong experience with Windows Server (2016/2019/2022) administration.
- Hands-on experience with Linux distributions such as Red Hat Enterprise Linux (RHEL), CentOS, Ubuntu, or SUSE.
- Extensive knowledge of Active Directory, Azure AD, DNS, DHCP, Group Policy, LDAP, and certificate services.
- Experience managing VMware vSphere, ESXi, vCenter, Hyper-V, and virtualization technologies.
- Strong knowledge of enterprise storage solutions (SAN/NAS) and RAID configurations.
- Experience with backup and disaster recovery tools such as Veeam, Commvault, Rubrik, or Veritas NetBackup.
- Experience administering Microsoft 365, Exchange Server, Teams, and SharePoint is desirable.
- Knowledge of AWS, Azure, or GCP infrastructure services.
- Strong scripting experience using PowerShell, Bash, or Python for automation.
- Experience with infrastructure monitoring tools such as SolarWinds, Zabbix, Nagios, PRTG, or SCOM.
- Understanding of networking concepts including TCP/IP, VLANs, VPN, routing, switching, DNS, and firewalls.
- Familiarity with infrastructure automation tools such as Ansible, Terraform, or Puppet is an advantage.
- Knowledge of ITIL processes, change management, and incident management.
Preferred Qualifications:
- Bachelor's degree in Computer Science, Information Technology, or a related discipline.
- Certifications such as Microsoft Certified (Azure Administrator/Windows Server), VMware VCP, Red Hat Certified Engineer (RHCE), AWS Certified SysOps Administrator, or ITIL Foundation are preferred.
- Experience in enterprise data center or cloud migration projects.
Skills
System Administration, IT Operations, DNS, LDAP, ESXi, Hyper-V, Linux, Windows Server