Hmmmm. The worst optimized site I've encountered in my career was probably just a few weeks back :) This was a site with a number of verticals where the front-end teams for each vertical were given the autonomy to decide how they were going to ship their part of the site.
As it turns out, this didn't end well.
One thing we hope can change this is encouraging more teams to adopt performance budgets and stick closely to them. There's no way the web can compete on mobile if we're going to send down so much code that accomplishes so little.
Oh, other stories.
There are so many ridiculous perf stories out there :)
Oh my goodness this is making me squirm.
OMG six different versions of the same library is definitely the result of poor communication. I can't wait for an AI powered browser opening alerts saying "please tell those developer fools that did this website to talk to each other :D"
The imaging thing is all very common.
I've seen galleries/grids of images rendered using the original images uploaded by the operator, which obviously were neither checked for size nor resized automatically.
Those stories sound like they're really easy to repeat though.
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