Comment by ToucanLoucan
Comment by ToucanLoucan 8 days ago
Downloading =/= executing. Downloading 60 kb of compressed JavaScript isn't the problem, the problem is running that JavaScript, and all the resulting web calls that JavaScript will do, and all the resulting compute it will take to... I dunno, make the button round or whatever. Load time is no longer a solid metric for a good experience, that's very late 00's of anyone to say, the metric now is how long until the page is laid out, and the controls on it are responsive?
Edit: Also how hot is my phone?
absolutely. page performance is the result of a hairball of initial asset loads, AJAX calls, ad-hoc roundtrips, telemetry bloat, ...
It's so convoluted, and very app specific. Core web vitals provide the right framework to think about what is relevant, but in reality your app likely requires dedicated instrumentation to capture these phases accurately.