System Administrator – Windows & AD

About the role

We are looking for a skilled System Administrator to join ADENTIS and take ownership of our Windows Server and Microsoft 365 environments. You will ensure the reliability, security and performance of core directory and messaging services while supporting a fast‑growing team.

Key responsibilities

• Administer, maintain and support Windows Server infrastructure with a strong focus on Active Directory.
• Manage AD objects, including users, groups, computers, GPOs and permissions.
• Monitor, troubleshoot and resolve issues related to AD, DNS, DHCP and authentication services.
• Administer Microsoft Exchange (on‑premise and online) and Office 365 environments.
• Perform system updates, patching, backups and recovery tests to ensure availability and compliance.
• Collaborate with infrastructure, security and support teams on operations and projects.
• Document configurations, procedures and operational processes.

Required profile

• Proven experience as a Windows System Administrator with hands‑on AD management.
• Strong knowledge of Windows Server, AD, GPO, DNS, DHCP and authentication mechanisms.
• Experience with PowerShell scripting for automation.
• Experience administering Microsoft Exchange and Office 365, including Exchange Online and Hybrid setups.
• Excellent troubleshooting and communication skills for both technical and non‑technical stakeholders.
• EU citizenship or Portuguese work visa/residency.
• Availability to work on‑site two to three days per week.

Required skills

• Windows Server
• Active Directory
• Group Policy Objects (GPO)
• DNS
• DHCP
• PowerShell
• Microsoft Exchange (On‑Prem & Online)
• Office 365
• Azure
• AWS

What we offer

• Great work‑life balance with a flexible routine.
• Health benefits for you and your family.
• Team‑building activities and access to 300+ discount protocols.
• Continuous professional development sponsored by our Training & Certification department.
• Regular feedback through a personalized performance plan.
• Comprehensive career progression with structured performance reviews.