performance.now() ’25 Day 1 part 1

It sounds like a simple question, but if you've been working in performance long enough, you know the answer is far from straightforward. In this Day 1 keynote, Tammy asks questions—from neuroscience to business metrics—that get you thinking about how you create, measure, and report your performance goals.

As awareness and tooling around site speed have been improving at a very exciting rate, has performance testing actually become any easier? In this talk, we'll look at practical tools and workflows so every test has a purpose and provides actionable, reliable data.

What if performance meant more than speed — what if it included how intuitively and equitably people can interact with your website? This session takes a practical look at how designing for accessibility contributes to more responsive, usable experiences, especially for disabled users, with ways to measure beyond load speed.

CSS content-visibility is a powerful tool that bypasses unnecessary rendering for offscreen content, drastically improving load times and responsiveness. This talk demonstrates benchmarks, practical techniques for content‑rich environments, and case studies.