Improving site performance by shipping more CSS (github.blog)

Performance is not complicated. You measure something and compare the numbers. Through my career I have encountered the following failures repeatedly:

* The complete inability to measure things. This is common among people with low social intelligence. Many people in this line of work cannot measure things and form all kinds of bullshit excuses. Cannot do it all as if they are disabled. Sometimes it is laziness, sometimes it’s autism masking, and sometimes it’s stupidity/ignorance where they believe they shouldn’t have to or are superior from convention alone.

* The shitty team argument. It’s common for people to intentionally avoid or discard measures because there is fear superior performance may indicate an operating deficit. The last thing anybody in software wants is to change approach if they are on a shitty team, because corporate developers are allergic to training people. This is often justified by asking what happens if you work on a team or about new hires.

* Throwing performance data away and lying about it. This is very common when performance data provides evidence that current conventions or favorite tools harm performance. If, for example querySelectors measure 100,000 times slower than some other approaches developers will pretend the performance evidence just doesn’t exist.

* Guessing. When people suck at what they do they invent their own performance realities. When people guess at software performance they are supremely wrong more than 80% of the time and tend to be wrong by multiple orders of magnitude.

Indeed, you need to waste a few years hurting user experience before investing a few years into migration and writing another "improved performance" blog post.

> that engineers should drop everything and work overtime on optimizing performance

The opposite, they should work less instead of more doing a worse job that results in scraping all their output later in a redesign

You’re conflating scale with bloat. At large orgs the problem is that nobody is willing to step back and say “this sucks”. Trying to get this fixed involves getting 6 teams to agree upon something with no clear owner for the outcome and with everyone incentivised for not being blamed if one of the other groups tanks the effort.

> engineers should drop everything and work overtime on optimising performance

No, we’re asking for it to be taken seriously by the organisation. I work in games, and on large projects we usually have a small team (2/3 people of a team of 80-100) who are constantly working on this stuff. Their work is “subjective” improvements but often it’s just building tooling and telling other groups what they need to fix.

   53K _long.css
   38K _short.css

   11K _long.css.br
  8.9K _short.css.br

Besides download size, smaller names improve parsing speed too.

The only thing hashing classes achieves is making it difficult for users to use ad blockers and/or custom CSS. I understand why e.g. Meta does it on their sites, but for GitHub it makes no sense.