Performance and people

I was helping a client with a bit of a performance audit this week. I really, really enjoy this work. It’s such a nice opportunity to get my hands in the soil of a website, so to speak, and suggest changes that will have a measurable effect on the user’s experience.

Not only is web performance a user experience issue, it may well be the user experience issue. Page speed has a proven demonstrable direct effect on user experience (and revenue and customer satisfaction and whatever other metrics you’re using).

It struck me that there’s a continuum of performance challenges. On one end of the continuum, you’ve got technical issues. These can be solved with technical solutions. On the other end of the continuum, you’ve got human issues. These can be solved with discussions, agreement, empathy, and conversations (often dreaded or awkward).

I think that, as developers, we tend to gravitate towards the technical issues. That’s our safe space. But I suspect that bigger gains can be reaped by tackling the uncomfortable human issues.

This week, for example, I uncovered three performance issues. One was definitely technical. One was definitely human. One was halfway between.

The technical issue was with web fonts. It’s a lot of fun to dive into this aspect of web performance because quite often there’s some low-hanging fruit: a relatively simple technical fix that will boost the performance (or perceived performance) of a website. That might be through resource hints (using link rel=“preload” in the HTML) or adjusting the font loading (using font-display in the CSS) or even nerdier stuff like subsetting.

In this case, the issue was with the file format of the font itself. By switching to woff2, there were significant file size savings. And the great thing is that @font-face rules allow you to specify multiple file formats so you can still support older browsers that can’t handle woff2. A win all ‘round!

The performance issue that was right in the middle of the technical/human continuum was with images. At first glance it looked like a similar issue to the fonts. Some images were being served in the wrong formats. When I say “wrong”, I guess I mean inappropriate. A photographic image, for example, is probably going to best served as a JPG rather than a PNG.

But unlike the fonts, the images weren’t in the direct control of the developers. These images were coming from a Content Management System. And while there’s a certain amount of processing you can do on the server, a human still makes the decision about what file format they’re uploading.

I’ve seen this happen at Clearleft. We launched an event site with lean performant code, but then someone uploaded an image that’s megabytes in size. The solution in that case wasn’t technical. We realised there was a knowledge gap around image file formats—which, let’s face it, is kind of a techy topic that most normal people shouldn’t be expected to know.

But it was extremely gratifying to see that people were genuinely interested in knowing a bit more about choosing the right format for the right image. I was able to provide a few rules of thumb and point to free software for converting images. It empowered those people to feel more confident using the Content Management System.

It was a similar situation with the client site I was looking at this week. Nobody is uploading oversized images in order to deliberately make the site slower. They probably don’t realise the difference that image formats can make. By having a discussion and giving them some pointers, they’ll have more knowledge and the site will be faster. Another win all ‘round!

At the other end of continuum was an issue that wasn’t technical. From a technical point of view, there was just one teeny weeny little script. But that little script is Google Tag Manager which then calls many, many other scripts that are not so teeny weeny. Third party scripts …the bane of web performance!

In retrospect, it seems unbelievable that third-party JavaScript is even possible. I mean, putting arbitrary code—that can then inject even more arbitrary code—onto your website? That seems like a security nightmare!

Remember when I did a countdown of the top four web performance challenges? At the number one spot is other people’s JavaScript.

Now one technical solution would be to remove the Google Tag Manager script. But that’s probably not very practical—you’ll probably just piss off some other department. That said, if you can’t find out which department was responsible for adding the Google Tag Manager script in the first place, it might we well be an option to remove it and then wait and see who complains. If no one notices it’s gone, job done!

More realistically, there’s someone who’s added that Google Tag Manager script for their own valid reasons. You’ll need to talk to them and understand their needs.

Again, as with images uploaded in a Content Management System, they may not be aware of the performance problems caused by third-party scripts. You could try throwing numbers at them, but I think you get better results by telling the story of performance.

Use tools like Request Map Generator to help them visualise the impact that third-party scripts are having. Talk to them. More importantly, listen to them. Find out why those scripts are being requested. What are the outcomes they’re working towards? Can you offer an alternative way of providing the data they need?

I think many of us developers are intimidated or apprehensive about approaching people to have those conversations. But it’s necessary. And in its own way, it can be as rewarding as tinkering with code. If the end result is a faster website, then the work is definitely worth doing—whether it’s technical work or people work.

Personally, I just really enjoy working on anything that will end up improving a website’s performance, and by extension, the user experience. If you fancy working with me on your site, you should get in touch with Clearleft.

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.

Website Speed Test

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

If Not React, Then What? - Infrequently Noted

Put the kettle on; it’s another epic data-driven screed from Alex. The footnotes on this would be a regular post on any other blog (and yes, even the footnotes have footnotes).

This is a spot-on description of the difference between back-end development and front-end development:

Code that runs on the server can be fully costed. Performance and availability of server-side systems are under the control of the provisioning organisation, and latency can be actively managed by developers and DevOps engineers.

Code that runs on the client, by contrast, is running on The Devil’s Computer. Nothing about the experienced latency, client resources, or even available APIs are under the developer’s control.

Client-side web development is perhaps best conceived of as influence-oriented programming. Once code has left the datacenter, all a web developer can do is send thoughts and prayers.

As a result, an unreasonably effective strategy is to send less code. In practice, this means favouring HTML and CSS over JavaScript, as they degrade gracefully and feature higher compression ratios. Declarative forms generate more functional UI per byte sent. These improvements in resilience and reductions in costs are beneficial in compounding ways over a site’s lifetime.

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.”

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.