traintimes.org.uk performance notes

I love, love, *love, traintimes.org.uk—partly because it’s so useful, but also because it’s so fast. I know public transport is the clichéd use-case when it comes to talking about web performance, but in this case it’s genuine: I use the site on trains and in airports.

Matthew gives a blow-by-blow account of the performance optimisations he’s made for the site, including a service worker. The whole thing is a masterclass in performance and progressive enhancement. I’m so glad he took the time to share this!

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Moving on from React, a Year Later

Many interactions are not possible without JavaScript, but that doesn’t mean we should look to write more than we have to. The server doing something useful is a requirement for building an interesting business. The client doing something is often a nice-to-have.

There’s also this:

It’s really fast

One of the arguments for a SPA is that it provides a more reactive customer experience. I think that’s mostly debunked at this point, due to the performance creep and complexity that comes in with a more complicated client-server relationship.

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Website Speed Test

Here’s a handy free tool from Calibre that’ll give your website a performance assessment.

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How Microsoft Edge Is Replacing React With Web Components - The New Stack

“And so what we did is we started looking at, internally, all of the places where we’re using web technology — so all of our internal web UIs — and realized that they were just really unacceptably slow.”

Why were they slow? The answer: React.

“We realized that our performance, especially on low-end machines, was really terrible — and that was because we had adopted this React framework, and we had used React in probably one of the worst ways possible.”

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The State of ES5 on the Web

This is grim:

If you look at the data below on how popular websites today are actually transpiling and deploying their code to production, it turns out that most sites on the internet ship code that is transpiled to ES5, yet still doesn’t work in IE 11—meaning the transpiler and polyfill bloat is being downloaded by 100% of their users, but benefiting none of them.

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Every website and web app should have a service worker | Go Make Things

Needless to say, I agree with this sentiment.

I’ve worked with a lot of browser technology over the years. Service workers are pretty mind-blowing.

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