Senior Security Systems Administrator

Key Responsibilities

• Lead administration and optimization of security platforms, including SIEM, EDR/XDR, vulnerability management, log management, email security, and identity protection systems.
• Investigate and respond to complex security alerts, incidents, and system anomalies, including containment, root cause analysis, recovery coordination, and post-incident improvements.
• Design and refine alerting logic, dashboards, detection rules, and correlation use cases within SIEM and monitoring platforms.
• Lead security hardening efforts across Windows systems, Active Directory, application platforms, and supporting infrastructure.
• Oversee security patching strategy and coordination for servers, endpoints, and infrastructure platforms, especially for critical or high-risk vulnerabilities.
• Serve as an escalation point for advanced endpoint protection, malware, ransomware, identity, and suspicious activity investigations.
• Lead vulnerability management activities, including prioritization, remediation planning, validation, and trend analysis.
• Administer and optimize Microsoft O365 security controls, including Defender, Conditional Access, MFA, Exchange security, and identity governance-related controls.
• Partner with Compliance and leadership teams on audits, risk assessments, evidence collection, control maturity, and remediation planning.
• Develop and maintain security standards, technical procedures, architecture documentation, and incident response playbooks.
• Provide technical leadership on security initiatives, tool improvements, and cross-functional infrastructure projects.
• Mentor Associate and intermediate-level administrators by providing guidance, review, and knowledge transfer.
• Participate in and help coordinate high-severity on-call response and escalation activities.
• Identify automation opportunities that improve visibility, consistency, response time, and operational resilience.

Required Qualifications

• Bachelor’s degree in Computer Science, Information Systems, Cybersecurity, or a related field; or equivalent work experience.
• Minimum of 5–7 years of progressive experience in systems administration, security operations, or infrastructure security roles.
• Strong hands-on experience with enterprise security tools, including SIEM, EDR/XDR, vulnerability management, and identity/access controls.
• Advanced proficiency with Windows Server, Active Directory, Group Policy, and system hardening practices.
• Strong understanding of virtualization, hosting, and production infrastructure technologies, including VMware, Hyper-V, and OpenShift.
• Working knowledge of scripting and automation tools such as PowerShell, Bash, or Ansible.
• Demonstrated ability to handle complex troubleshooting, incident response, documentation, and cross-functional coordination.

Preferred Qualifications

• Experience with Linux administration and hybrid Windows/Linux environments.
• Experience with cloud security in Azure, AWS, or Google Cloud environments.
• Relevant certifications such as Security+, CySA+, CISSP, SC-200, AZ-500, or equivalent.
• Familiarity with firewall administration, backup/security resilience controls, and enterprise security architecture concepts.
• Exposure to ITIL, change management, or formal project leadership practices.

Key Skills & Attributes

• Advanced analytical and problem-solving skills.
• Strong independent judgment and ownership of complex work.
• Ability to lead technical initiatives and influence peers across teams.
• Strong written and verbal communication, including the ability to explain risk and technical issues clearly.
• Commitment to operational excellence, continuous improvement, and mentoring others.

Work Environment & Benefits

• ISCorp offers a competitive salary and a full benefits package, including health, dental, 401(k), and profit sharing. Our Mequon headquarters provides a collaborative office environment with minimal travel requirements and an in-house fitness facility available to employees.

About ISCorp