Principal Microsoft 365 Engineer

About the Team

Oracle Cloud Infrastructure (OCI) is looking for an experienced principal Microsoft 365 Engineer to join our Enterprise Collaboration Services team.

Our team is responsible for delivering secure, reliable, and scalable collaboration and messaging services that support Oracle’s global workforce of more than 150,000 users.

We manage business-critical enterprise technologies, including Microsoft 365, Exchange Online, SharePoint Online, OneDrive, Microsoft Entra ID, and Proofpoint, ensuring that employees around the world can communicate and collaborate effectively.

You’ll join a distributed engineering team working across multiple locations, including the UK and Czech Republic, and contribute to the continued improvement of Oracle’s enterprise collaboration infrastructure.

About the Role

We’re looking for a principal, hands-on engineer with strong expertise in Microsoft 365, enterprise messaging, and email security.

This role offers a combination of technical engineering projects, platform improvements, and operational support within a large-scale enterprise environment.

You’ll take ownership of complex technical initiatives, troubleshoot challenging production issues, and work closely with infrastructure, security, networking, and engineering teams to maintain and improve the reliability, performance, and security of our collaboration services.

We’re looking for someone who enjoys solving complex problems, works independently, and brings both technical depth and a proactive approach to engineering.

What You’ll Do

• Administer, maintain, and optimize Microsoft 365 services, including Exchange Online, Microsoft Teams, SharePoint Online, OneDrive for Business, Microsoft Entra ID, and Microsoft Purview.
• Manage enterprise messaging infrastructure, including mail flow, routing, transport rules, and email security.
• Administer and optimize Proofpoint email security solutions, ensuring secure and reliable messaging across the organization.
• Implement and maintain email authentication and security technologies such as DMARC, SPF, and DKIM.
• Troubleshoot complex technical issues across Microsoft 365, enterprise messaging, identity, and infrastructure services.
• Support identity and access management technologies, including Active Directory, Conditional Access, MFA, SSO, and Privileged Identity Management.
• Improve operational efficiency and service reliability through PowerShell automation and modern AI-assisted engineering tools.
• Contribute to security, compliance, and governance initiatives using technologies such as Microsoft Defender for Office 365 and Microsoft Purview.
• Independently drive technical projects and collaborate with global engineering teams on scalable, secure, and resilient solutions.
• Participate in an on-call rotation supporting business-critical collaboration and messaging services.

What We’re Looking For

We’re looking for an experienced engineer (lead) who has worked with Microsoft 365 and enterprise messaging technologies in complex, large-scale environments.

Your background should include:

• 6+ years of hands-on experience administering Microsoft 365 in enterprise environments.
• Strong expertise in Exchange Online, enterprise messaging architecture, mail flow, and troubleshooting.
• Extensive hands-on experience administering Proofpoint in enterprise environments, ideally 6+ years.
• Experience with email security and authentication technologies, including DMARC, SPF, and DKIM.
• Strong knowledge of Microsoft Entra ID (Azure AD), Active Directory, and identity security technologies.
• Experience supporting Microsoft Teams, SharePoint Online, and OneDrive for Business.
• Practical experience with PowerShell and automating Microsoft 365 administrative processes.
• Strong troubleshooting skills across Microsoft 365, messaging, security, and infrastructure environments.
• Experience working with Windows Server and Linux systems.
• The ability to independently own technical initiatives while collaborating effectively with distributed engineering teams.

Familiarity with Microsoft Purview, Microsoft Defender for Office 365, Microsoft Intune, and AI-assisted automation tools such as ChatGPT or Codex would be beneficial.

Relevant Microsoft or Proofpoint certifications are an advantage but are not mandatory.

Why Join Us?

• Enterprise scale:
  Work on critical collaboration and messaging platforms supporting more than 150,000 users globally.
• Technical ownership:
  Take responsibility for complex engineering projects and challenging technical problems.
• Modern technologies:
  Work across Microsoft 365, enterprise messaging, email security, identity management, and automation.
• Global collaboration:
  Partner with experienced engineers and technical teams across multiple locations.
• Continuous improvement:
  Help improve the reliability, security, and efficiency of Oracle’s enterprise collaboration environment.

Location & Working Arrangement

This position is based in the Dublin area and currently supports remote working, subject to Oracle’s workplace policies.

The role includes participation in an on-call rotation, with weekday coverage and occasional weekend support.

Applicants must have the right to work in Ireland without employer-sponsored work authorization.

Interested?

If you have strong Microsoft 365 and enterprise messaging experience, enjoy solving complex technical challenges, and are looking for a role where you can make a meaningful impact at enterprise scale, we’d be happy to hear from you.

Join Oracle Cloud Infrastructure and help support the collaboration technologies that connect Oracle’s global workforce.