We are seeking a highly experienced Senior System Administrator to support and evolve our hybrid on‑premises and cloud infrastructure in a Geneva‑based, international environment. This role requires strong expertise in Microsoft technologies, Azure, identity and security services, and virtualization, with a high standard of reliability and professionalism.
The position plays a critical role in ensuring availability, security, and compliance of core IT services supporting business‑critical operations.
Key Responsibilities
- Design, implement, and maintain Windows Server environments (on‑premises and cloud)
- Administer and optimize Microsoft Azure infrastructure and services
- Manage and support Microsoft 365 / Office 365, including Exchange Online and collaboration services
- Administer Microsoft Entra ID (Azure AD), including hybrid identity, synchronization, conditional access, and authentication policies
- Manage Active Directory, ADFS, DNS, and core identity services
- Operate and maintain VMware virtualization platforms
- Administer Microsoft Exchange environments (on‑premises, hybrid, and/or cloud)
- Manage Public Key Infrastructure (PKI), including certificate authorities and trust models
- Ensure certificate lifecycle management (TLS/SSL, authentication, encryption) across servers, applications, and services
- Ensure high availability, backup, disaster recovery, monitoring, and capacity planning
- Troubleshoot complex infrastructure, identity, and authentication issues
- Apply security best practices in line with Swiss and international compliance requirements
- Participate in audits, risk assessments, and documentation efforts
- Collaborate closely with internal IT teams and international stakeholders
- Maintain clear technical documentation and operational procedures
- Provide technical leadership and mentoring to less experienced administrators