TH3RA Consulting
Senior Network Engineer (Core Routing / ACI / Firewall)
TH3RA ConsultingGermany2 days ago
Full-timeRemote FriendlyInformation Technology
  • Applicants must hold German or EU citizenship to qualify for this role.
  • Location: Remote in Germany - need to be based in Germany or relocate.


IT means everything to us!

At TH3RA, we deliver IT solutions that empower global businesses to achieve their digital ambitions. With deep expertise and a commitment to excellence, we support clients across industries in building resilient, scalable, and secure infrastructures.


Role overview

We are URGENTLY hiring an L3 Senior Network Engineer (Core Routing / ACI / Firewall) to join a Network & SecOps team responsible for implementing, operating, and continuously evolving campus and data center networks. Cisco ACI for data center networks, with a strong emphasis on automation, monitoring, and multi-ISP interconnectivity.


  • Location: Remote in Germany - need to be based in Germany or relocate
  • Occasionally on-site in DE as needed
  • Contract: Freelancer or Employee (DE-contract)
  • Clearance: German security clearance (Ü2/SÜG) or eligibility to obtain
  • Start: ASAP | Duration: 12+ months (extendable)
About the Role

We’re looking for a hands-on Senior Network Engineer to support mission-critical enterprise networks across core routing, data center fabrics (Cisco ACI), and firewalls. You’ll design, implement, and troubleshoot high-availability environments and collaborate with platform, security, and operations teams.

Key Responsibilities
  • Design, implement, manage, and troubleshoot network infrastructure, including data center, campus, and WAN environments.
  • Operate and optimize network components such as switching and routing fabrics, firewalls, routers, switches, and F5 load balancers.
  • Build and maintain ACI fabrics and Layer 2/Layer 3 overlays, including VXLAN and EVPN.
  • Take ownership of incident, problem, and change management for network services; develop comprehensive runbooks and documentation.
  • Contribute to capacity planning, performance optimization, and lifecycle management, including upgrade strategies.
  • Collaborate with security teams to ensure policy enforcement, segmentation, and compliance across all environments.
Required Skills & Experience
  • Core routing & DC networking: BGP/MP-BGP, OSPF/IS-IS, HSRP/VRRP, VLAN/VRF, VXLAN/EVPN.
  • Cisco ACI (policy model, tenants/EPGs/BDs, contracts, APIC).
  • Firewalls & ADC: enterprise firewalls and F5 LTM/GTM/WAF (operations & troubleshooting).
  • TCP/IP fundamentals and packet-level troubleshooting.
  • Strong across vendor NOS: IOS-XE, NX-OS, IOS-XR, Arista EOS (others a plus).
  • Proven ability to deliver in large, distributed, high-availability environments.
  • Excellent English (B2+). German is a plus.
Nice to Have
  • Network automation: Ansible, Python or other scripting.
  • Tooling & observability: GitHub, Ansible, Grafana, Prometheus.
  • IaC/CI pipelines for network changes; REST/NETCONF/gNMI familiarity.
  • Exposure to SD-WAN, IPAM/DNS/DHCP, Zero Trust, micro-segmentation.
Clearance & Work Authorization
  • Active Ü2/SÜG clearance strongly preferred; otherwise, eligible and willing to obtain.
  • Citizenship: must hold citizenship from an EU or NATO member country (client requirement).
  • Residence in Germany required for remote engagement (with occasional travel within DE).
Engagement Details
  • Hours: CET business hours; occasional planned maintenance windows.
  • Rate: Competitive, please propose a daily rate (EUR) and availability.


📨 How to apply: Send your CV (in English), with ref: ACIENG087, to [email protected] or apply below.


Thank you!

T3 Team

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