performance.now() 2025
Introduction to day 2
About this presentation
<div data-test-render-count="1"> <div> <div class="group relative pb-3" data-is-streaming="false"> <div class="font-claude-response relative leading-[1.65rem] [&_pre>div]:bg-bg-000/50 [&_pre>div]:border-0.5 [&_pre>div]:border-border-400 [&_.ignore-pre-bg>div]:bg-transparent [&_.standard-markdown_:is(p,blockquote,h1,h2,h3,h4,h5,h6)]:pl-2 [&_.standard-markdown_:is(p,blockquote,ul,ol,h1,h2,h3,h4,h5,h6)]:pr-8 [&_.progressive-markdown_:is(p,blockquote,h1,h2,h3,h4,h5,h6)]:pl-2 [&_.progressive-markdown_:is(p,blockquote,ul,ol,h1,h2,h3,h4,h5,h6)]:pr-8"> <div> <div class="grid-cols-1 grid gap-2.5 [&_>_*]:min-w-0 standard-markdown"> <p class="whitespace-normal break-words">To open Day 2 of the conference, Tim Kadlec reflects on the principle of "stubborn empathy" for users that has guided his web performance career, inspired by Nate Koechly's foundational talk on professional front-end engineering. He identifies two critical threats to this user-first approach: the monoculture of single-browser testing and development, and the uncritical adoption of AI-generated code. Kadlec celebrates the recent cross-browser support for core web vitals metrics in Firefox and Safari as a major step forward, demonstrating how testing across different browsers reveals performance issues that would otherwise go unnoticed and harm real users.</p> <p class="whitespace-normal break-words">The talk challenges the web performance community to resist the commodification of the web by AI agents and tools that prioritize generation speed over long-term quality. With data showing that AI-assisted coding produces 154% larger pull requests and 9% more bugs, Kadlec argues that human judgment and advocacy for users becomes more critical than ever. He calls for the next era of web performance to be defined by the courage to build defensively, vet code ruthlessly, and aim for experiences that aren't just fast but genuinely delightful—closing the door on the margin that allows outside forces to control and diminish the open web.</p> </div> </div> </div> </div> </div> </div>