The third proposal
A proposal landed in August to rebuild a client platform from scratch, and when I went digging in the shared drive I found two older ones saying almost exactly the same thing.
AbortController
The thing everybody knows as the way to cancel a fetch is also the tidiest way to remove a pile of event listeners, and the second use has changed more of my code than the first.
:is() and :where()
Two selectors that look interchangeable in every example anybody writes, and differ on the one thing that actually causes problems later.
Button colors and Black Friday
A former coworker asked whether to take an in-house job, and the most useful thing I learned from mine is to ask who gets the interesting work.
We billed them for the cleanup
A WordPress site I'd done the front end for at my old agency spent about two months redirecting phones to a sweepstakes page, and the invoice for cleaning it up was larger than a year of the maintenance nobody had ever sold them.
Four sentences somebody could check
A client asked what progressive enhancement meant in practice and the 4 of us on the call produced about 90 seconds of gesturing, not one word of which anybody could have written down.
details and summary
An accordion with keyboard support, correct announcement and no JavaScript at all, which most of us reimplemented by hand for about a decade before noticing.
They deleted the line
I asked a developer on an outside team why a line was there, meaning it literally, and they deleted it, which is roughly when I understood that the approve button had been doing the talking.
I couldn't read it in the sun
I took my phone out to the front steps to look at a page I'd built, couldn't read a word of it, and then found that every pair of colors on it cleared the threshold with room to spare.
Shopify collection limits
A row of six related products came out one card short on about a third of a client's catalog, and the thing eating the missing card was a limit I'd never read about, being spent by a block I hadn't written.
It got slower while I optimized it
I added lazy loading to every image on a site in about 20 minutes, felt pleased with myself, and then measured it and found the pages were taking longer to show their main content than before I started.
prefers-reduced-motion
An operating system setting that has been sitting there since 2013 telling you somebody gets motion sick, and the two-line stylesheet that is the whole of respecting it.