Lead Unix/Linux Security Engineer

Our client is seeking a Lead Unix/Linux Security Engineer to support and enhance enterprise Linux authentication, identity integration, and operating system security across a large-scale environment. This hands-on engineering role is responsible for configuring, troubleshooting, and maintaining secure authentication services while partnering with infrastructure, security, and networking teams to ensure secure and reliable access to critical systems.

The ideal candidate has extensive experience with SSSD, Kerberos, LDAP, Active Directory integration, and Linux security hardening, along with a strong background supporting enterprise Linux environments., * Configure, maintain, and troubleshoot enterprise Linux authentication services using SSSD.

• Integrate Linux systems with Active Directory, LDAP, and Kerberos.
• Diagnose and resolve authentication failures, SSSD caching issues, domain join problems, and cross-realm trust issues.
• Configure and maintain Linux PAM stack and sudo policies.
• Implement Linux security hardening and secure access best practices.
• Coordinate with firewall and network teams to establish secure communication between Unix/Linux servers.
• Create, modify, and manage Linux groups and permissions supporting enterprise applications.
• Troubleshoot production issues related to password expiration, access permissions, group privileges, and authentication.
• Support endpoint privileged management solutions and enterprise identity integrations.
• Develop and maintain automation using Bash, Python, Ansible, or Puppet.
• Participate in production change windows outside of normal business hours as needed.

• 8+ years of experience as a Unix/Linux Systems Engineer, Linux Security Engineer, or similar role.
• Strong hands-on experience with System Security Services Daemon (SSSD).
• Experience configuring and supporting:
• Kerberos
• LDAP
• Active Directory integration
• Advanced experience administering:
• Red Hat Enterprise Linux (RHEL)
• CentOS
• Ubuntu
• Strong knowledge of:
• Linux authentication
• PAM configuration
• sudo policy management
• Enterprise identity management
• Experience troubleshooting:
• Authentication failures
• Password expiration
• SSSD caching
• Domain joins
• Cross-realm trust issues
• Experience implementing Linux hardening and secure access models.
• Experience coordinating with firewall teams on secure Linux communications.
• Automation experience using Bash, Python, Ansible, or Puppet.

Preferred Qualifications

• Experience supporting large enterprise Linux environments.
• Background in the financial services or insurance industry.
• Familiarity with Endpoint Privileged Management (EPM) solutions.
• Previous USAA experience is a plus, but not required.

Top Skills

• SSSD (System Security Services Daemon) - Expert-level experience
• Kerberos, LDAP, and Active Directory Integration - Advanced experience
• Enterprise Linux Administration (RHEL/CentOS/Ubuntu) - Advanced experience

$75 - $80 an hour - Full-time, Contract