Notes I took/tweeted and some of my favorite live-tweets by others during her presentation follow.
On starting a new project:
One example of why it’s important: Amazon observed a 1% decrease in revenue for every 100ms added to page load.
Always set a performance budget right from the start:
“Quality is stability, performance, and reliability.” She reminds us that performance is a design feature, not a technical concern. Pages should weigh no more than 400-600kb, and make no more than 15 requests. Consider limiting fonts to 100kb.
On comparison & keeping things in check:
She says check your sites on webpagetest.org. Also check your competitors so you make sure your site is competitive with theirs. (Make it faster!)
On working with clients:
On style guides & testing:
She mentions Trulia created a style guide, and now their site loads 21% faster now and they reduced unused CSS by 135kb. (Read more.)
“The important point is to look at every design decision, right through the design/build process, as something that has consequence…” -Mark Perkins
Yesenia shared lots of examples, comparisons, and details, so if you get a chance to see her speak or if she shares her slides online, check them out to get the full effect. (Looks like she’ll be speaking in SF in November.)