Performance Engineer, Kernel and Memory

Cloudflare•San Francisco, CA

9d•Hybrid

About The Position

At Cloudflare, we have our eyes set on an ambitious goal: to help build a better Internet. Today the company runs one of the world’s largest networks that powers approximately 25 million Internet properties, for customers ranging from individual bloggers to SMBs to Fortune 500 companies. Cloudflare protects and accelerates any Internet application online without adding hardware, installing software, or changing a line of code. Internet properties powered by Cloudflare all have web traffic routed through its intelligent global network, which gets smarter with every request. As a result, they see significant improvement in performance and a decrease in spam and other attacks. Cloudflare was named to Entrepreneur Magazine’s Top Company Cultures list and ranked among the World’s Most Innovative Companies by Fast Company. We realize people do not fit into neat boxes. We are looking for curious and empathetic individuals who are committed to developing themselves and learning new skills, and we are ready to help you do that. We cannot complete our mission without building a diverse and inclusive team. We hire the best people based on an evaluation of their potential and support them throughout their time at Cloudflare. Come join us!

Requirements

Deep expertise in the Linux kernel memory-management subsystem: the page allocator, virtual memory and memory mapping, reclaim, and the locking and concurrency that hold it together.
A track record of upstream Linux contribution, ideally including maintainership or sustained work in MM or an adjacent subsystem.
Strong systems programming in C, with the judgement to make high-risk changes to shared infrastructure safely.
Ability to dive deep into a complex codebase while keeping the fleet-wide picture in mind, and to own a problem and its outcome rather than a single patch.
Clear communication with engineers across many teams, since the symptoms of an MM problem usually show up far from the MM code.

Nice To Haves

Strong understanding of Linux kernel internals pertaining to memory management
Experience troubleshooting and resolving performance issues in large-scale distributed systems.
Experience with large scale configuration/deployment management.

Responsibilities

Diagnose and fix performance and scalability bottlenecks in the Linux kernel memory-management subsystem, informed by real production telemetry at a scale few environments can offer.
Land your work upstream. We expect MM changes to go to mainline first and want you to keep doing the maintainership and review work that earns standing in the community.
Build and extend low-overhead kernel instrumentation (tracepoints, BPF, perf) so we keep measuring before we change, and prove the impact afterwards.
Partner with kernel, networking, storage, and product engineers across the company to turn observed system behavior into concrete MM improvements.
Set technical direction for how Cloudflare uses, tunes, and evolves kernel memory management as we push utilization higher.