Senior Network & Systems Administrator
SSS is looking for a Senior Network & Systems Administrator to own our network, cloud and Microsoft 365 infrastructure. You'll be the go-to technical expert for keeping it reliable, scalable and high-performing, and for taking it forward. The role reports to the IT Manager and works closely with the Senior Cybersecurity Engineer. It is offshore-based, serving Samir Group (KSA), and works full-time on-site from our Heliopolis office.
Key Responsibilities
Own the design, implementation and optimization of the enterprise network: LAN/WAN, VLANs, routing (OSPF, BGP, static), Layer 2/3 switching and multi-site connectivity (site-to-site VPN, SD-WAN).
Plan and lead infrastructure projects end to end, such as network redesigns, cloud migrations, upgrades and new site rollouts.
Architect and administer Microsoft Azure and AWS environments: VMs, virtual networks (VNets, NSGs, route tables), Private Endpoints and Private DNS zones, storage, backup and disaster recovery, and cost optimization.
Own Microsoft Entra ID, Exchange (Online and On-Premises) and Microsoft 365 administration, including hybrid identity through Entra Connect (sync, writeback, Hybrid Join) and hybrid Exchange.
Harden and govern the Microsoft 365 tenant: MFA, Conditional Access, least-privilege admin roles and PIM, break-glass accounts, Secure Score and SPF/DKIM/DMARC.
Lead device and application management through Microsoft Intune: Autopilot, enrollment, app packaging, configuration and compliance policies, and PowerShell scripts and remediations.
Operate and maintain firewalls and VPNs in line with the security policies set by the Cybersecurity function.
Manage public DNS, Cloudflare (DNS, proxy, WAF) and the SSL/TLS certificate lifecycle, keeping DNS records clean to prevent risks such as subdomain takeover.
Support incident response with the Cybersecurity function: contain compromised accounts and devices (disable/reset accounts, revoke sessions, isolate devices with Microsoft Defender) and lead root cause analysis.
Support pre-go-live security checks of published web applications (vulnerability assessment against OWASP Top 10) together with the Cybersecurity function.
Design and support IP telephony, SIP and QoS.
Set up capacity planning, monitoring and alerting so issues are caught before they affect users.
Act as the final escalation point for complex infrastructure incidents, troubleshooting methodically across DNS, network, firewall/ports and change history.
Apply change management on every change: SOPs, action plans, testing and rollback plans.
Define technical standards and keep architecture documentation and network diagrams up to date.
Mentor IT support staff and share technical knowledge across the team.
Recommend technology improvements and support the IT Manager with roadmap and budget planning.
Requirements
Bachelor's degree in IT, Computer Science or a related field.
5+ years of experience in network and systems administration.
Deep hands-on expertise in routing (OSPF, BGP), switching, VLANs and LAN/WAN design.
Strong experience with Azure (VMs, VNets, NSGs, Private Endpoints, Entra ID and Entra Connect); solid AWS experience.
Proven experience administering Exchange (hybrid), Microsoft 365 and Intune (Autopilot, compliance policies) in enterprise environments, including Conditional Access and PIM.
Hands-on experience with enterprise firewalls (Fortinet, Palo Alto, Cisco or similar), public DNS, Cloudflare/WAF and SSL/TLS certificates.
Practical incident response experience with Microsoft Defender (Endpoint, Identity); exposure to vulnerability assessment (OWASP, Burp Suite, Nessus or similar) is a plus.
Track record of leading infrastructure projects from planning through delivery, with clear change management.
Certifications such as CCNP, AZ-104/AZ-305 or MS-102 are strongly preferred.
Excellent written and spoken English.