Software Engineer - Linux Kernel

Description:

Fastly helps people stay better connected with the things they love. Fastly’s edge cloud platform enables customers to create great digital experiences quickly, securely, and reliably by processing, serving, and securing our customers’ applications as close to their end-users as possible — at the edge of the Internet. The platform is designed to take advantage of the modern internet, to be programmable, and to support agile software development.

Fastly’s customers include many of the world’s most prominent companies, including Git Hub, Yelp, Paramount, and Jet Blue.

We're building a more trustworthy Internet. Come join us.

Posting Open Date: 10/07/2026

Anticipated Posting Close Date*: 11/6/26

* Job posting may close early due to the volume of applicants.

Fastly's Kernel and Host Networking team builds and ships the Linux kernel that runs on every server in our 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 up streamed and safely running on thousands of servers.

The work spans networking, XDP and eBPF, memory, performance and hardware enablement. It also spans layers. Our kernel is the datapath of a distributed system whose control planes are constantly pushing new state to the fleet, so staying correct under change is part of the job. Formal CS education is not required; demonstrable experience is what matters.

• 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 up streaming
• 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