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JavaScript Performance Engineer

Engineering | San Francisco, CA | Full Time

Job Description

About Us:

At CloudFlare, we have our eyes set on an ambitious goal -- to build a better web. We believe that with our talented team, smart technology and engaged users we can solve some of the biggest problems on the web. We already serve more web traffic than Twitter, Bing, Wikipedia, Amazon, Apple and Instagram combined. Anytime we push a line of code, it affects over 200 million web surfers overnight. We are still a small team, well-funded, growing quickly and focused on building a world-class company.


CloudFlare is looking for an engineer to join our front-end optimization team. The browser is the front-line in the battle for a faster, more interactive websites. At CloudFlare, we are building the next-generation resource distribution platform that changes the way browsers load websites. This position will work on a variety of web performance projects covering the spectrum of front-end performance topics, such as automated JavaScript loading optimization, JavaScript pre-execution, DOM-level CSS analysis, dynamic image resizing and automated mobile-device optimization. The automated solutions that you build will work across hundred of thousands of websites, making the web faster for more than 450 million web surfers every month. 


  • Experience working with JavaScript and other functional programming languages
  • Understand the similarities and differences across browsers (young and old)
  • Background doing measurements and benchmarking
  • Interest in creating tools and libraries that need to scale to every website on the Internet
  • A belief that tested code is happy code
  • Excited by the idea of optimizing complex solutions to general problems that all websites face
  • Experience with a continuous integration work flow and using source control (we use git)

Bonus Points:

  • Experience with performance optimization on mobile devices
  • Appreciation for emerging JavaScript standards like common.js and an interest in helping them be adopted


We offer competitive salaries, equity, fantastic health benefits plan, a new laptop, monthly CalTrain / BART pass for commuters and the opportunity to work with a smart, motivated team where you will see your contribution daily. Our sunny offices are based in SOMA in San Francisco, CA.

Sound like somewhere you'd thrive? We'd love to hear from you. Submit your resume and a short paragraph to introduce yourself.

CloudFlare is a security company.  All prospective employees will be subject to an extensive background check.

CloudFlare is an equal opportunity employer and does not discriminate against any employee or applicant on the basis of age, color, disability, gender, national origin, race, religion, sexual orientation, veteran status, or any classification protected by federal, state, or local law.