Senior Engineer, Cilium CNI & Cloud Networking

What You’ll Do
Network Services Team
The Network Services team builds and operates the foundational networking that powers CoreWeave’s Kubernetes platforms at cloud scale. The team is responsible for container networking, connectivity, and network services that support large-scale, GPU-driven workloads across regions and environments. They focus on scalability, reliability, security, and performance while delivering intuitive platforms for internal teams and customers.

About the Role
As a Senior Engineer focused on our Cilium-based CNI, you will design, build, and operate the container networking layer that underpins CoreWeave’s Kubernetes platforms. Day to day, you will work on evolving our CNI stack to support large, high-density GPU clusters with demanding throughput and latency requirements. You will partner closely with Kubernetes, Infrastructure, and Network Services engineers to ensure the platform is highly available, observable, and secure. This role spans architecture, implementation, and operations, with ownership from prototype through production. You will also help shape how our networking platform scales for future growth.

Who You Are

• 5+ years of experience as a Software Engineer or Systems Engineer working on cloud infrastructure or large-scale distributed systems.
  
  
• Hands-on production experience with Cilium CNI (or equivalent advanced CNIs), including cluster configuration and lifecycle management.
  
  
• Strong understanding of Cilium’s eBPF datapath, policy model, and load-balancing mechanisms.
  
  
• Deep knowledge of cloud networking concepts, including VPCs, subnets, routing, security groups/ACLs, NAT, and ingress/egress architectures.
  
  
• Experience designing multi-tenant network architectures with strong isolation and security.
  
  
• Solid grounding in TCP/IP, dynamic routing (e.g., BGP), ECMP, MTU/fragmentation, and overlay/underlay networking (VXLAN, Geneve, encapsulation).
  
  
• Experience with network observability and troubleshooting across L3–L7.
  
  
• Proficiency in at least one systems language such as Golang or C/C++.
  
  
• Experience working in modern CI/CD environments.
  
  
• Experience operating Kubernetes at scale, including cluster lifecycle management and debugging networking issues across pods, nodes, and external services.
  
  
• Demonstrated ownership of complex systems end-to-end.
  
  

Preferred

• Experience operating cloud-scale network services across tens of thousands of nodes and multiple regions.
  
  
• Contributions to Cilium, Kubernetes, or related open-source networking projects.
  
  
• Experience with eBPF development and performance tuning.
  
  
• Experience building Kubernetes operators or controllers.
  
  
• Familiarity with service meshes, multi-cluster networking, or cluster mesh solutions.
  
  
• Experience in GPU-heavy, HPC, or other performance-sensitive environments.