Technical Leadership & Mentorship: Act as a lead for complex projects; provide technical guidance and mentorship to mid-level and junior engineers to foster a culture of continuous learning.
Infrastructure Architecture: Design, implement, and evolve resilient LAN/WAN and Data Center architectures (Cisco Nexus, VPC) that align with business growth.
Network Automation: Drive operational efficiency by implementing automation techniques (e.g., dynamic routing link backup).
Security & Compliance: Lead the hardening of network security postures. Manage Next-Gen Firewalls (Fortinet, Check Point, FortiGate, NAC (Aruba ClearPass/Cisco ISE), and Zero Trust frameworks.
Lifecycle Management: Proactively manage the lifecycle of network assets, including capacity planning, security advisories, firmware orchestration, and performance tuning.
Cloud Integration: Design and manage hybrid-cloud connectivity (AWS/Azure/GCP), ensuring seamless integration between on-premise data centers and cloud VPCs.
Escalation Support: Serve as the final escalation point (L3) for complex network outages, participating in an on-call rotation to ensure 24/7 service availability.
Vendor & Stakeholder Management: Collaborate with external vendors and internal DevOps/System teams to integrate network solutions.

8+ years of hands-on experience in enterprise-grade network environments.
BSc/MSc in Computer Science, Network Engineering, or a related field.
Core Networking: Expert-level command of switching and routing protocols (BGP, OSPF, EIGRP, STP, LACP, HSRP).
Network Security: Deep expertise in NGFW (FortiGate, Check Point, Cisco ASA / FTD), VPN technologies (IPsec, SSL), and **SD-WAN **implementation.
Wireless & Access Control: Advanced knowledge of Enterprise WiFi (Aruba Central) and Identity Management (ClearPass or Cisco ISE).
Application Delivery: Experience with L4-L7 Load Balancing (F5 BIG-IP LTM) and Web Application Firewalls (F5 Big-IP AWAF/FortiWeb).
Cloud & Virtualization: Proven experience with Cloud Networking (VPC, Subnetting, Network ACL/Security Groups, Site-to-Site VPN with on-premises DCs, ExpressRoute) and Virtualization (VMware NSX, VRFs, VDOMs, VSX, FPR).
Certifications: Professional level certification (e.g., CCNP, NSE 4-7, CCSA-CCSE) are required; Expert level (CCIE) is a significant plus.
Fluent: Excellent command of both Greek and English (written and verbal) is essential for this role.

We offer a competitive base salary and benefits, directly dependent on the candidate’s qualifications and skills.
The real excitement comes from working closely with a dynamic, smart, agile, and highly motivated team in a competitive and fast-paced environment.
Upstream is an equal-opportunity employer.

Senior Network Engineer

Key skills