Senior Systems Administrator

We are seeking a Senior Systems Administrator to oversee the design, implementation, maintenance, and security of our IT infrastructure. This role is responsible for managing networking, firewalls, servers, virtual machine hosts, user accounts, licenses, and various related IT services. The ideal candidate has a strong background in enterprise-level IT systems, cybersecurity best practices, and troubleshooting complex technical issues. Key Responsibilities: Network & Security Administration: Manage and maintain enterprise networking infrastructure, including routers, switches, VLANs, and VPNs. Administer firewalls, intrusion detection/prevention systems (IDS/IPS), and network security policies. Ensure network uptime, performance, and redundancy through best practices and monitoring tools. Implement and maintain network segmentation, access controls, and encryption protocols. Oversee physical and virtual server environments, including Windows Server, Linux, and VMware/Hyper-V. Configure, monitor, and maintain domain controllers, DNS, DHCP, and Active Directory. Manage storage solutions, including SAN/NAS devices, backups, and disaster recovery plans. Optimize performance, capacity planning, and patch management for all servers. User & Identity Management: Administer user accounts, groups, and permissions in Active Directory, Entra, and other identity platforms. Manage Microsoft 365 and other enterprise collaboration tools. Oversee single sign-on (SSO), multi-factor authentication (MFA), and identity access management (IAM). Software Licensing & Compliance: Track and manage software licenses, renewals, and compliance with vendor agreements. Maintain documentation of IT assets, software installations, and configurations. IT Operations & Support: Provide Tier 3 escalation support for IT issues related to networking, servers, and infrastructure. Develop and maintain IT documentation, standard operating procedures (SOPs), and disaster recovery plans. Conduct security audits, vulnerability assessments, and penetration testing. Work closely with IT leadership to define infrastructure strategies and long-term roadmaps. Coordinate with vendors and service providers for hardware, software, and network services. Lead infrastructure projects, upgrades, and migrations with minimal downtime. Train and mentor junior IT staff on best practices and system administration. Required Qualifications: Education: Bachelor’s degree in Computer Science, Information Technology, or equivalent experience. Experience: 5+ years in enterprise IT administration with a focus on networking, servers, and security. Certifications (Preferred): Cisco Certified Network Associate (CCNA) or higher VMware Certified Professional (VCP) CompTIA Security+ or CISSP Technical Skills: Strong knowledge of Windows Server, Linux, and virtualization (VMware, Hyper-V). Familiarity with firewalls (Fortinet, Cisco ASA, Palo Alto, or similar) and network security. Hands-on experience with Active Directory, Entra, Group Policy, and IAM. Proficiency in PowerShell, Bash, or Python for automation and administration. Understanding of cloud environments (Azure, AWS, Google Cloud) and hybrid infrastructure. Familiarity with backup solutions, disaster recovery, and business continuity planning. Soft Skills: Excellent problem-solving and analytical skills. Strong documentation and communication abilities. Ability to work independently and manage multiple priorities. Commitment to security best practices and continuous learning. Seniority level Seniority level Mid-Senior level Employment type Employment type Full-time Job function Job function Information Technology Industries Industrial Machinery Manufacturing, Manufacturing, and Civil Engineering Referrals increase your chances of interviewing at Alliance Steel OKC by 2x Sign in to set job alerts for “Senior System Administrator” roles. Oklahoma City, OK $45,000.00-$60,000.00 6 months ago Windows System Administrator / Application Release Manager Windows System Administrator / Application Release Manager Cyber Intelligence Technical Specialist (Night-Shift) Business and Information Technology Division Adjunct - IT Emphasis We’re unlocking community knowledge in a new way. Experts add insights directly into each article, started with the help of AI. #J-18808-Ljbffr