Senior System Administrator

TL;DR

Senior System Administrator (Networking & Infrastructure): Maintaining, improving, and securing company IT infrastructure including Windows servers, Active Directory, Microsoft 365, and multi-site enterprise networks with an accent on advanced networking, firewalls, and SD-WAN. Focus on designing VLAN configurations, Cisco switching, Fortinet firewalls, Wi-Fi segmentation, and executing network modernization projects with minimal downtime.

Location: Warsaw, Poland.

Company

Global vendor of an agentic CRM & workflow platform with no-code and AI at its core, helping organizations automate workflows for thousands of clients in over 100 countries.

What you will do

• Administer Windows Server environments, Active Directory, Group Policies, Microsoft 365, Exchange, and endpoint protection.
• Design and maintain multi-VLAN networks with Cisco switches, VLANs, trunking, routing, and link aggregation across offices.
• Configure enterprise Wi-Fi (Ruckus, Aruba, Meraki), Fortinet firewalls, SD-WAN with failover, DHCP, DNS, and secure remote access.
• Provide advanced troubleshooting, prepare rollback plans, and execute risk-aware infrastructure changes.
• Maintain documentation, diagrams, IP plans, and operational procedures for enterprise IT.

Requirements

• 5+ years in System Administration / IT Infrastructure
• Strong expertise in Windows Server, Active Directory, Microsoft 365, Exchange, endpoint security; support for Windows/macOS.
• Advanced enterprise networking: TCP/IP, DNS, DHCP, VLANs, routing/switching, VPNs, SD-WAN.
• Hands-on with Cisco switches, Fortinet firewalls, enterprise Wi-Fi (Ruckus/Aruba/Meraki).
• Experience with multi-site segmented networks, troubleshooting, and security best practices.
• Proficiency in Ukrainian and English languages

Nice to have

• Virtualization, backup systems, scripting, automation.
• Certifications: CCNA/CCNP, Fortinet NSE, Microsoft, ITIL.
• Cloud or hybrid infrastructure experience.

Culture & Benefits

• Clear career paths, mentorship, continuous learning opportunities.
• Flexible work arrangements for productivity and well-being.
• Culture of recognition, impact, and innovative thinking.
• Competitive compensation and benefits package tailored to country and employment type.