Network Engineer

Circle B builds sustainable IT infrastructure for the AI and cloud era. For over a decade— we have designed and deployed datacenter, edge, and AI/HPC systems on Open Compute Project (OCP) hardware. We are independent, vendor-neutral, and ISO 9001 / 14001 / 27001 certified, with deployments across multiple countries.
Our newest initiative is a sovereign EU GPU cloud — operating under full Dutch/EU jurisdiction and beyond the reach of the US CLOUD Act, for regulated European organizations that cannot compromise on where their data lives.

The Role
Network Engineer — BGP / Juniper / EVPN-VXLAN / GPU Cluster Networking
The opportunity
We run our own hosting infrastructure and production network, and we’re looking for a hands-on Network Engineer who enjoys real ownership: operating core connectivity, improving reliability, and building out capabilities that directly matter to customers.
You’ll work on an environment with real routing (own ASN), real datacenter networking, and meaningful change-impact. If you like being close to the technology and seeing your work show up in production immediately, you’ll fit well.
What you'll do
Operate and improve our production network
Maintain and evolve our Juniper routing and switching environment.
Manage BGP operations on our ASN: routing policy, filtering, communities, troubleshooting, and traffic engineering.
Operate EVPN/VXLAN in production and help extend it as we grow.
Manage IPv4/IPv6 addressing and clean subnet allocation/assignment workflows.
Design and expand network capabilities
Independently translate customer requirements into practical network designs for our multi-tenant hosting environment, including addressing, VLAN/VXLAN segmentation, routing, firewalling, redundancy, and implementation planning, with senior design review available for more complex solutions.
Help design and implement our expansion into internet exchanges and peering, including planning, implementation, validation, and ongoing operations.
Implement routing-security best practices (e.g., RPKI/IRR hygiene and route-leak protections).
Network security
Perform security assessments of our existing network infrastructure, identifying vulnerabilities, architectural weaknesses, and opportunities for improvement.
Design and implement practical security improvements, including network segmentation, firewall policies, access controls, and protection of management infrastructure.
Maintain and improve our firewall environment, including policy management, rule hygiene, and secure customer isolation.
Help develop and implement network security measures, including DDoS mitigation, in collaboration with our external senior network consultant when needed.
Documentation, monitoring, and operational quality
Use Net Box as the source of truth for network inventory and IP addressing.
Improve monitoring, alerting, and network visibility, including telemetry, logging, and traffic analysis, using the existing toolchain and extending it where needed.
Create and maintain diagrams, runbooks, and change documentation to improve operational reliability.
Be helpful beyond networking when needed
When network workload is lighter, support adjacent infrastructure areas (Linux, virtualization, storage, automation, or occasional customer escalations) depending on your strengths and team priorities.
What we're looking for
Core requirements
Proven hands-on experience operating production networks, preferably in a multi-tenant hosting, datacenter, ISP, cloud, or service-provider environment.
Strong practical knowledge of:
Datacenter switching and L2/L3 fundamentals.
IPv4/IPv6 operations and addressing design.
Practical knowledge of EVPN/VXLAN, preferably with hands-on production experience.
Hands-on experience with network security,…