Vitol is a leader in the energy sector with a presence across the spectrum: from oil through to power, renewables and carbon.  From 40 offices worldwide, we seek to add value across the energy supply chain, including deploying our scale and market understanding to help facilitate the energy transition. To date, we have committed over $2 billion of capital to renewable projects, and are identifying and developing low-carbon opportunities around the world.

Our people are our business. Talent is precious to us and we create an environment in which individuals can reach their full potential, unhindered by hierarchy. Our team comprises more than 65 nationalities and we are committed to developing and sustaining a diverse work force. Learn more about us here.

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

Required Technical Skills & Experience

• Several years of experience as a Senior System Administrator in an enterprise environment
• Strong hands-on expertise in:
  • Microsoft Azure
  • Microsoft Entra ID (Azure AD)
  • Microsoft 365 / Office 365
  • Windows Server
  • VMware / Vsphere
  • Active Directory & ADFS
  • DNS, DHCP
  • Microsoft Exchange
  • PKI and certificate management
• Proven experience with hybrid (on‑premises and cloud) infrastructures
• Solid understanding of identity, authentication, encryption, and security principles
• Experience with PowerShell and automation is highly valued

Soft Skills & Personal Attributes

• Open-minded – comfortable working in a multicultural, international environment
• Reliable – trusted to operate and support critical systems
• Flexible – adaptable to changing priorities, projects, and operational needs
• Structured and methodical approach to problem-solving
• Strong communication skills in technical and business contexts
• Team player with a professional and service-oriented mindset

Languages

• English: professional working proficiency (required)
• French: working knowledge is a strong advantage

Nice to Have

• Microsoft / Azure certifications
• Experience in regulated environments (finance, trading, healthcare, international organizations)
• Familiarity with Swiss data protection and security standards
• Experience supporting international or multi-site infrastructures