Senior Systems Administrator (Windows/Linux) – Security

Precise Systems Inc.; San Diego (CA); Hybrid; USD 150,000 - 170,000; Full time

Benefits offered by this job

Health insurance

Life and accidental death coverage

Disability insurance

Retirement plans

Holiday pay

Employee-managed leave

Professional growth opportunities

Job summary

Precise Systems Inc. in San Diego seeks a System Administrator III to lead senior IT administration and security hardening across Windows, Linux, virtualization, and network environments. The role supports secure enterprise and tactical systems within government or defense-related settings.

This in-person position requires strong communication, patching, incident response, and collaboration with IT, cybersecurity, engineering, and program teams to sustain mission-ready IT infrastructure.

Qualifications

• Extensive system administration experience in Windows and Linux environments.
• Experience with security hardening, patching, and vulnerability remediation.
• Background in government, military, or mission-focused IT environments.
• Strong communication and leadership skills for team coordination.

Responsibilities

• Lead and support admin of Windows, Linux, ESXi, network, and tactical computing envs.
• Implement security hardening and maintain CMMC/ DISA STIG alignment.
• Remediate vulnerabilities, apply updates, document actions.
• Develop backup and recovery procedures and ensure data availability.
• Troubleshoot network infrastructure and tactical data pipelines.
• Provide senior guidance, mentorship, and stakeholder communication.

Skills

Windows

Linux

ESXi

Networking

Security hardening

CMMC

DISA STIG

Backup & recovery

Troubleshooting

Documentation

Leadership

Education

Bachelor’s Degree or Equivalent Experience

Current Security+ Certificate

Tools

VMware

Docker

Kubernetes

Ansible

PowerShell

Bash

Python

Job description

Precise Systems Inc. in San Diego seeks a System Administrator III to lead senior IT administration and security hardening across Windows, Linux, virtualization, and network environments. The role supports secure enterprise and tactical systems within government or defense-related settings.

This in-person position requires strong communication, patching, incident response, and collaboration with IT, cybersecurity, engineering, and program teams to sustain mission-ready IT infrastructure.