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Staff Software Engineer - Linux Kernel

Fastly

Denver · New York City, NY · San Francisco · USD 211,370-253,644 · 7+ years experience · Hybrid · Posted Oct 6, 2026

At a glance

Experience
7+ years experience
Workplace
Hybrid
Location
Denver · New York City, NY · San Francisco
Salary
USD 211,370-253,644

About the role

  • Fastly's Kernel and Host Networking team builds and ships the Linux kernel that runs on every server in the global edge network, and every customer request passes through it.
  • As a Staff engineer you own technical problems end to end: from a crash signature or a new NIC on the bench, through root cause and design, to a change that is upstreamed and safely running on thousands of servers.

Responsibilities

  • Set technical direction for kernel projects, own them end to end from problem statement to fleet rollout, and mentor engineers on the team
  • Take new servers, CPUs and NICs from first boot to full fleet: drivers, IRQ affinity, RSS and queue layout on high core count hosts
  • Improve datapath and transport performance with XDP, eBPF and protocol work based on IETF specifications
  • Debug problems that cross layers with application teams, such as MTU behavior, cgroup memory accounting and packet filtering
  • Develop and maintain kernel changes and Fastly kernel modules on our long term kernel line, and reduce our private delta by upstreaming
  • Make sure state pushed from control planes to eBPF and XDP programs is applied, verified and safe to roll back
  • Own kernel health in production: triage crashes, WARNs and regressions across the fleet, find the root cause and ship the fix
  • Own and improve the kernel release process and the signals behind it: CI, bake, canary, staged rollout and rollback across thousands of servers, plus crash metrics and drift detection that fire before customers notice
  • Join the on-call rotation, lead the kernel side of incidents and drive follow-up actions to closure

Requirements

  • 7+ years of related engineering experience, including substantial production C, with 3 of those years leading technical projects
  • Production Linux kernel development, including debugging use-after-free, refcount and leak bugs with KASAN, kdump, ftrace, perf or bpftrace
  • Working knowledge of the scheduler and memory management (EEVDF, memcg)
  • Experience managing a kernel patch stack and working with upstream communities
  • Solid understanding of the Linux network stack (TCP/IP, sk_buff lifecycle, qdiscs, NIC drivers) and XDP or eBPF, with deep expertise in at least one of these areas
  • Operational discipline: staged rollouts, canaries, kill switches, observability, postmortems and closing action items
  • Understanding of distributed systems: control plane and datapath consistency, partial failure and safe config rollout at fleet scale
  • Ability to design broadly scoped work and drive it across teams

Preferred qualifications

  • Upstream kernel contributions or subsystem maintainership
  • Deep Knowledge of Transport protocols from IETF RFCs: QUIC, TCP, ECN and L4S, MASQUE
  • Hardware enablement on AMD EPYC or Intel platforms, and NIC drivers such as mlx5, ice or i40e
  • Load balancing or traffic steering systems
  • CDN or large edge network environments
  • Container networking: network namespaces, veth, cgroups, and eBPF-based CNI datapaths

Benefits

  • Medical, dental, and vision insurance
  • Family planning
  • Mental health support along with Employee Assistance Program
  • Insurance (Life, Disability, and Accident)
  • Flexible Vacation policy
  • Up to 18 days of accrued paid sick leave
  • 401(k) (including company match)
  • Employee Stock Purchase Program
  • 11 paid local holidays
  • 12 paid company wellness days

Workplace

  • This position is open to remote and hybrid work locations in the United States.
  • This position may require travel as required by your role or requested by your manager.

Skills

  • C
  • Linux Kernel
  • KASAN
  • Kdump
  • Ftrace
  • Perf
  • Bpftrace
  • XDP
  • eBPF
  • TCP/IP
  • QUIC
  • ECN
Show all 15 skills
  • L4S
  • MASQUE
  • Mlx5

Fastly

Staff Software Engineer - Linux Kernel

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