Hell is other people’s JavaScript.
Third-party scripts are probably the #1 cause of poor performance and bad UX on the web.
Trust no one! Harry enumerates the reason why you should be self-hosting your assets (and busts some myths along the way).
There really is very little reason to leave your static assets on anyone else’s infrastructure. The perceived benefits are often a myth, and even if they weren’t, the trade-offs simply aren’t worth it. Loading assets from multiple origins is demonstrably slower.
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.
React is a non-transferable skill.
React proponents might claim that React will teach you modern UI, but from what I’ve seen it barely copes with modern UI.
autofocus is broken, custom elements don’t work in all but the experimental version, using any “modern” features likedialogor popovers requiresuseEffect, and the synthetic event system teaches you so little about how DOM actually works. This isn’t modern UI, it’s UI from 2013 at its inception. I don’t have the time left in my career to pick up UI paradigms that haven’t evolved much beyond from when Barack Obama was in office.When I mentor early career developers and they ask me what they should learn, I can’t say React, they don’t have time. I mean sure, pick up enough React to land you the inevitable job doing it, but it’s not going to level up your career.
“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.”
I want to be a part of a frontend culture that accepts and promotes our responsibilities to others, rather than wallowing in self-centred “DX” puffery. In the hierarchy of priorities, users must come first.
Alex doesn’t pull his punches in this four-part truth-telling:
The React anti-pattern of hugely bloated single-page apps has to stop. And we can stop it.
Success or failure is in your hands, literally. Others in the equation may have authority, but you have power.
Begin to use that power to make noise. Refuse to go along with plans to build YAJSD (Yet Another JavaScript Disaster). Engineering leaders look to their senior engineers for trusted guidance about what technologies to adopt. When someone inevitably proposes the React rewrite, do not be silent. Do not let the bullshit arguments and nonsense justifications pass unchallenged. Make it clear to engineering leadership that this stuff is expensive and is absolutely not “standard”.
Going back to school in Amsterdam.
DOM scripting and event handling.
Improving performance on The Session.
The behaviour is more consistent now.
Inside me there are two wolves. They’re both JavaScript.