Build resilient systems at scale
May 27–29, 2015 • Santa Clara, CA

Service workers - practical applications for performance and availability

Patrick Meenan (Facebook)
9:00am–10:30am Wednesday, 05/27/2015
Location: Ballroom CD
Average rating: ****.
(4.67, 52 ratings)
Slides:   1-PDF 

Prerequisite Knowledge

Familiarity with how websites are constructed and loaded would be helpful.


Service workers are a fairly new browser technology that is just starting to make it into the field. They provide a way for site owners to inspect or modify all the network requests that originate from their pages/apps, and effectively work as an in-browser proxy with full JavaScript programmability.

We will explore how they can be used to progressively enhance existing applications, with trivial changes to the applications themselves, to:

  • Eliminate third-party single points of failure
  • Implement smarter caching strategies
  • Add support for custom compression/delta encoding schemes
  • Take control of browser fetching behavior/prioritization

We will provide working examples, explore how the implementations work, and open up a world of possibilities for developers to do even more exciting things with them.

Photo of Patrick Meenan

Patrick Meenan


Patrick Meenan has been working on web performance in one form or another for the last 15 years, and is currently working at Google on Chrome performance and to make the web faster. He created the popular open-source WebPageTest web performance measurement tool, runs the free instance of it at, and can frequently be found in the forums helping site owners understand and improve their website performance.