Senior Engineer, Cilium CNI & Cloud Networking

Core Weave is The Essential Cloud for AI™. Built for pioneers by pioneers, Core Weave delivers a platform of technology, tools, and teams that enables innovators to build and scale AI with confidence. Trusted by leading AI labs, startups, and global enterprises, Core Weave combines superior infrastructure performance with deep technical expertise to accelerate breakthroughs and turn compute into capability. Founded in 2017, Core Weave became a publicly traded company (Nasdaq: CRWV) in March 2025.

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The Network Services team builds and operates the foundational networking that powers Core Weave’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.

As a Senior Engineer focused on our Cilium-based CNI, you will design, build, and operate the container networking layer that underpins Core Weave’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.

• 5+ years of experience as a Software, Systems, or Network 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, Python, 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.

• 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.

We believe in investing in our people and value candidates who bring diverse experiences — even if you’re not a 100% match on paper. If some of this sounds like you, we’d love to talk.

• You love solving complex distributed systems and networking challenges at scale.
• You’re curious about cloud-native networking, eBPF, and Kubernetes internals.
• You’re an expert in building reliable, scalable infrastructure that runs in production.

At Core Weave, we work hard, have fun, and move fast! We’re in an exciting stage of hyper‑growth that you will not want to miss out on. We’re not afraid of a little chaos, and we’re constantly learning. Our team cares deeply about how we build our product and how we work together, which is represented through our core values:

• Be Curious at Your Core
• Act Like an Owner
• Empower Employees
• Deliver Best‑in‑Class…