Software Engineer, Spectrum - Cloudflare

About the Role

As a member of the Spectrum team within Packet Processing, you will take shared ownership of a critical, high-scale L4 proxy. You will help evolve it into the next generation of Cloudflare's non-HTTP traffic platform, working on a product with massive existing scale.

Responsibilities

• Spectrum Edge Dataplane (Go): Manage TCP/UDP connection acceptance, forwarding, TLS termination, PROXY protocol, connection accounting, and eBPF integrations.
• Spectrum Control Plane (Go): Develop application configuration APIs, provisioning, and global configuration distribution systems.
• Cross-Dataplane Integrations: Collaborate on integrations with Unimog (L4 load balancing), Magic Transit, and Argo Smart Routing.
• Operational Excellence: Maintain analytics pipelines, observability, on-call rotations, incident response, and technical debt reduction.
• Roadmap Evolution: Shape the future of Spectrum as the L4 counterpart to Cloudflare's HTTP proxy stack.

Desirable Skills & Experience

• Experience building and shipping large-scale, reliable, highly distributed systems.
• Strong programming experience in Go; familiarity with or willingness to learn Rust.
• Solid understanding of L3/L4 networking (TCP, UDP, IP, NAT, anycast, packet flows).
• Proficiency with Linux networking primitives (sockets, eBPF, network namespaces, netfilter/nftables, tc).
• Experience designing and integrating RESTful APIs.
• Comfort with production operations, including on-call and root-cause analysis.
• Ability to reason about and evolve complex, existing systems at scale.

Bonus Points

• Experience with TLS termination or L4/L7 proxies (Envoy, HAProxy, nginx stream).
• Knowledge of ClickHouse, Kafka, or large-scale analytics pipelines.
• Experience with globally-distributed KV or config-push systems.
• Prior work on DDoS mitigation, L4 load balancing, or high-throughput edge network daemons.
• Contributions to open-source networking or proxy projects.