Senior Systems and Security Administrator

About the role

The Senior Systems & Security Administrator is a hands-on role responsible for managing, securing, and supporting a hybrid enterprise IT environment. The position supports Windows Server and Linux/Ubuntu infrastructure, Microsoft 365, Microsoft Entra ID, Active Directory, Exchange Online, AWS, Azure, and Odoo-based business applications. This role manages system and cloud operations, identity and access, system maintenance, patching, monitoring, backup and recovery, vulnerability remediation, Tier 2/3 support, automation, and technical documentation. The administrator independently troubleshoots complex infrastructure issues and applies least-privilege and security best practices.

Responsibilities

• Administer Windows Server environments, including Active Directory, DNS, DHCP, Group Policy, file services, patching, and system lifecycle activities.
• Administer Linux and Ubuntu servers, including users and permissions, services, patching, performance monitoring, log analysis, and troubleshooting.
• Perform server provisioning, configuration, upgrades, patching, backup validation, recovery testing, and documentation.
• Monitor system availability, capacity, performance, and backup status, and proactively address issues.
• Administer Active Directory, Microsoft Entra ID, and Microsoft 365 identity services.
• Manage the full user lifecycle, including account provisioning, access changes, group membership, license assignment, and offboarding.
• Support hybrid identity environments, including directory synchronization and synchronization troubleshooting.
• Administer Exchange Online, including user and shared mailboxes, distribution and security groups, mailbox permissions, licensing, and mail flow.
• Manage Conditional Access, multifactor authentication, enterprise applications, single sign-on, role-based access, and privileged access.
• Conduct periodic reviews of user accounts, group memberships, licenses, and access permissions.
• Administer AWS environments, including compute, networking, identity and access, security groups, DNS, load balancing, storage, monitoring, and database services.
• Support Azure virtual machines, identity services, networking, storage, monitoring, and security controls.
• Maintain least-privilege access, cloud identity controls, firewall rules, security configurations, and monitoring.
• Support Odoo environments, including Linux hosting, PostgreSQL connectivity, application availability, logs, backups, and troubleshooting.
• Collaborate with Odoo developers and business stakeholders on deployments, integrations, scheduled jobs, performance issues, and access requests.
• Participate in cloud migration, modernization, automation, and infrastructure improvement initiatives.
• Maintain Windows, Linux/Ubuntu, cloud, and business application environments according to established security standards and operating procedures.
• Perform operating system, application, and security patching, coordinate maintenance windows, and validate system health after changes.
• Apply secure configuration standards and maintain appropriate administrative and least-privilege access.
• Review system, application, and cloud logs for