About Us

At Cloudflare, we have our eyes set on an ambitious goal: to help build a better Internet. Today, Cloudflare runs one of the world’s largest distributed networks that powers more than 10 trillion requests per month, which is nearly 10 percent of all Internet requests worldwide. Cloudflare protects and accelerates any Internet application online without adding hardware, installing software, or changing a line of code.

Our customers range from Fortune 500 companies and nonprofits to small businesses and budding entrepreneurs. We are working to create a faster, more secure, and more reliable experience for anyone online and given the scale at which we operate, our mission is big. Our team is hard at work shaping the future of the Internet by solving some of its toughest challenges. Come join us!

About the Department

Cloudflare’s Engineering Team builds and runs the software that handles about 10% of HTTP requests on the Internet today. We also build and run the internal tools that builds and runs our software. The Engineering Team is split into two groups: one handles product development and the other handles operations. Product development covers both new features and functionality and scaling our existing software to meet the challenges of a massively growing customer base. The operations team handles one of the world’s largest networks with data centers in 102 cities worldwide.

What you'll do

Do you know why a Client saying "Hello" needs an Extension but not a Ticket?

Excited when RTO gets smaller than SRTT? Puzzled to see SYN packet longer than 56 bytes? Always wanted to perform a kernel, not a heart, bypass? Worried if QUIC can be amplified? Wondering if BPF supports XOR operation?

If so, Cloudflare's world-famous DDoS mitigation team is growing and looking for people like you. By joining the team, you are making sure the 10% of the web we serve is protected from any kind of DDoS, analyzing the attacks we do receive and educating the rest of the world on how to fix the DDoS.

You will build tools to help our SRE team with day-to-day mitigations including automating L3 & L7 DDoS mitigations. You'll maintain the Kernel fork we use which includes backporting mainline features and implementing improvements in the TCP stack as well as writing systemtap scripts to aid with kernel debugging. And finally, making sure our sflow and netflow on-line realtime streaming systems are up, no matter what.

(We mostly program in C (kernel panic at EIP=0x0), Golang (wait, was that a GC spike?) and Python (pip install scapy). We do not hold pagers, although we are expected to fix our system if they crash.)

Examples of desirable skills, knowledge and experience

  • Strong understanding of networking at at least L3 layer (what is IPID again?)
  • Strong low level debugging skills (what does tcpdump -ttttt do?)
  • Strong understanding of Linux, Unix and network stack design (Why can't you dup(2) epoll fd? How does strace work?)
  • Reasonable understanding of HTTP layer (can one send the "Host" header twice?)
  • Reasonable experience in C.
  • Willingness to learn Golang.

What Makes Us Special


We’re not just a highly ambitious, large-scale technology company. We’re a highly ambitious, large-scale technology company with a soul. Fundamental to our mission to help build a better Internet is protecting the free and open Internet.

Project Galileo: We equip politically and artistically important organizations and journalists with powerful tools to defend themselves against attacks that would otherwise censor their work, technology already used by Cloudflare’s enterprise customers--at no cost.

Project Athenian: We created Athenian Project to ensure that state and local governments have the highest level of protection and reliability for free, so that their constituents have access to election information and voter registration.

Path Forward Partnership: Since 2016, we have partnered with Path Forward, a nonprofit organization, to create 16-week positions for mid-career professionals who want to get back to the workplace after taking time off to care for a child, parent, or loved one. We released to help fix the foundation of the Internet by building a faster, more secure and privacy-centric public DNS resolver. This is available publicly for everyone to use - it is the first consumer-focused service Cloudflare has ever released. Here’s the deal - we don’t store client IP addresses never, ever. We will continue to abide by our privacy policy and ensure that no user data is sold to advertisers or used to target consumers.

Sound like something you’d like to be a part of? We’d love to hear from you!

Cloudflare hires the best people based on an evaluation of their abilities and effectiveness. We don't discriminate against employees on the basis of any other personal characteristic or any classification protected by federal, state or local law.

Apply for this Job
* Required
Almost there! Review your information then click 'Submit Application' to apply.

File   X
File   X