Staff Software Engineer - Linux Kernel

Fastly's Kernel and Host Networking team builds and operates the Linux kernel running across their global edge network. As a Staff Software Engineer, you will own technical problems end-to-end—from kernel crashes and hardware enablement through design, implementation, and fleet rollout—spanning networking, XDP, eBPF, memory, performance, and distributed systems consistency.

What You'll Do

• Set technical direction for kernel projects and mentor engineers; own projects end-to-end from problem statement through fleet rollout
• Bring new servers, CPUs and NICs from first boot to full fleet deployment: develop drivers, configure IRQ affinity, RSS and queue layout on high core count hosts
• Improve datapath and transport performance using XDP, eBPF and IETF-specified protocols; debug cross-layer issues with application teams
• Develop and maintain kernel changes and Fastly kernel modules on long-term kernel branches; reduce private delta by upstreaming contributions
• Own kernel production health: triage crashes, WARNs and regressions across the fleet, identify root causes and ship fixes; lead on-call rotation and incident response

What You Need

• 7+ years of related engineering experience including substantial production C, with 3+ years leading technical projects
• Production Linux kernel development experience, including debugging use-after-free, refcount and leak bugs with KASAN, kdump, ftrace, perf or bpftrace
• Working knowledge of the Linux scheduler and memory management (EEVDF, memcg)
• Experience managing a kernel patch stack and collaborating 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 area

Nice to Have

• Upstream kernel contributions or subsystem maintainership
• Deep knowledge of transport protocols from IETF RFCs: QUIC, TCP, ECN, L4S, MASQUE
• Hardware enablement on AMD EPYC or Intel platforms and NIC driver experience (mlx5, ice, i40e)
• Experience with load balancing, traffic steering systems, CDN or large edge network environments; container networking with network namespaces, veth, cgroups and eBPF-based CNI datapaths

$211,370–$253,644 per year; equity and discretionary bonus programs; comprehensive benefits including medical, dental, vision; family planning, mental health support, life/disability/accident insurance; 401(k) with company match, ESPP, flexible vacation, 18 days accrued paid sick leave, 11 paid holidays, 12 paid wellness days