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CloudflareCloudflareAustin, TX

Systems Engineer, Spectrum

Systems Engineer on Cloudflare's Spectrum team building and evolving the high-scale L4 proxy and non-HTTP traffic platform. Requires strong Go experience, deep L3/L4 networking knowledge, Linux primitives including eBPF, and production operations skills.

Salary not listed
Hybrid5+ YOEBackend Engineering

About the role

Responsibilities

  • Work on the Spectrum edge dataplane (Go): TCP/UDP connection acceptance and forwarding, TLS termination, PROXY protocol, connection accounting, and eBPF integrations
  • Work on the Spectrum control plane (Go): application configuration APIs, provisioning, and the systems that push config globally to every edge machine
  • Handle cross-dataplane integrations: how Spectrum fits together with Unimog for L4 load balancing, with Magic Transit for IP transit, with Argo Smart Routing for accelerated origin paths, etc.
  • Drive operational excellence: analytics pipelines, observability, on-call, incident response, and paying down technical debt in a product with a long production history
  • Contribute to roadmap evolution: help shape where Spectrum goes next as the L4 counterpart to our HTTP proxy stack
  • Partner closely with the rest of Packet Processing, other Traffic Management teams, DDoS, DNS, Core SRE, and Edge SRE to solve problems that span the entire Cloudflare stack

Requirements

  • Experience building and shipping large-scale, reliable, highly distributed systems
  • Strong programming experience in Go; familiarity with or willingness to work in Rust is a plus
  • Solid understanding of L3 and L4 networking: TCP, UDP, IP, connection state, NAT, anycast, and packet flows
  • Experience with Linux networking primitives — sockets, eBPF, network namespaces, netfilter/nftables, tc
  • Experience designing and integrating RESTful APIs and backend systems
  • Comfort with operating what you build in production — on-call rotations, incident response, and root-cause analysis
  • Ability to reason about existing systems at scale: reading unfamiliar code, understanding hidden dependencies, and safely evolving software that has been in production for years
  • Excellent debugging and optimization skills, particularly around performance and connection lifecycle issues
  • Focus on clarity in written and verbal communication; ability to work across teams to land shared solutions

Nice-to-Haves

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

Skills

GoRusttcpudpipnatanycastebpflinux networkingREST APIstls terminationproxy protocolenvoyhaproxynginx stream

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