Link tags: speed

Constraints and the Lost Art of Optimization — Den Odell

The entire intellectual and creative output of a team that reinvented personal computing fits in a space that, today, we wouldn’t think twice about wasting on a single font file.

Somewhere in the years that followed we’ve lost the creative solutions, the art of optimization, that being constrained in that way produces.

The best engineers I’ve worked with carry this instinct even when others might think it crazy. They impose their own constraints. They ask what this would look like if it had to be half the size, or run twice as fast, or use a tenth of the memory. Not because anyone demanded it, but because just by thinking there could be a better, more efficient solution, one often emerges.

JS-heavy approaches are not compatible with long-term performance goals

Frameworks like React are often perceived as accelerators, or even as the only sensible way to do web development. There’s this notion that a more “modern” stack (read: JS-heavy, where the JS ends up running on the user’s browser) allows you to be more agile, release more often with fewer bugs, make code more maintainable, and ultimately launch better sites. In short, the claim is that this approach will offer huge improvements to developer experience, and that these DevEx benefits will trickle down to the user.

But over the years, this narrative has proven to be unrealistic, at best. In reality, for any decently sized JS-heavy project, you should expect that what you build will be slower than advertised, it will keep getting slower over time while it sees ongoing work, and it will take more effort to develop and especially to maintain than what you were led to believe, with as many bugs as any other approach.

Where it comes to performance, the important thing to note is that a JS-heavy approach (and particularly one based on React & friends) will most likely not be a good starting point; in fact, it will probably prove to be a performance minefield that you will need to keep revisiting, risking a detonation with every new commit.

The Main Thread Is Not Yours — Den Odell

Every millisecond you spend executing JavaScript is a millisecond the browser can’t spend responding to a click, updating a scroll position, or acknowledging that the user did just try to type something. When your code runs long, you’re not causing “jank” in some abstract technical sense; you’re ignoring someone who’s trying to talk to you.

This is a great way to think about client-side JavaScript!

Also:

Before your application code runs a single line, your framework has already spent some of the user’s main thread budget on initialization, hydration, and virtual DOM reconciliation.

I Built the Same App 10 Times: Evaluating Frameworks for Mobile Performance | Loren Stewart

A very, very deep dive into like-for-like comparison of JavaScript frameworks. The takeaway:

Nuxt demonstrates that established “big three” frameworks can achieve next-gen performance when properly configured. Vue’s architecture allows competitive mobile web performance while maintaining a mature ecosystem. React and Angular show no path to similar results.

And the real takeaway:

Mobile is the web. These measurements matter because mobile web is the primary internet for billions of people. If your app is accessible via URL, people will use it on phones with cellular connections. Optimizing for desktop and hoping mobile is good enough is backwards. The web is mobile. Build for that reality.

“AI is inevitable” is bullshit · Eric Eggert

LLMs are useful when you need a compromise between fast and good. You will never get a good outcome fast.

I’m afraid we are settling into a status of good enough when using “AI,” which is especially hurtful for accessibility.

It’s time for modern CSS to kill the SPA - Jono Alderson

SPAs were a clever solution to a temporary limitation. But that limitation no longer exists.

Use modern server rendering. Use actual pages. Animate with CSS. Preload with intent. Ship less JavaScript.

I’m more proud of these 128 kilobytes than anything I’ve built since | by Mike Hall | Jul, 2025 | Medium

I don’t normally link to articles on Medium—I respect you too much—and I do wish this were written on Mike Hall’s own site, but this is just too good not to share.

And don’t dismiss this as a nostalgiac case study from the past:

At no point did the constraints make the product feel compromised. Users on modern devices got a smooth experience and instant feedback, while those on older devices got fast, reliable functionality. Users on feature phones got the same core experience without the bells and whistles.

The constraints forced us to solve problems in ways we wouldn’t have considered otherwise. Without those constraints, we could have just thrown bytes at the problem, but with them every feature had to justify itself. Core functionality had to work everywhere, and without JavaScript crutches proper markup became essential.

This experience changed how I approach design problems. Constraints aren’t a straitjacket, keeping us from doing our best work; they are the foundation that makes innovation possible. When you have to work within severe limitations, you find elegant solutions that scale beyond those limitations.

(optional.is) Latency and the Sea

Brian’s excellent comparison of network latency and the nervous system of animals:

If an earthquake occurs in California USA, halfway around the globe someone can find out faster than a blue whale detects something has touched its tail.

Website Speed Test

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

Pivoting From React to Native DOM APIs: A Real World Example - The New Stack

One dev team made the shift from React’s “overwhelming VDOM” to modern DOM APIs. They immediately saw speed and interaction improvements.

Yay! But:

…finding developers who know vanilla JavaScript and not just the frameworks was an “unexpected difficulty.”

Boo!

Also, if you have a similar story to tell about going cold turkey on React, you should share it with Richard:

If you or your company has also transitioned away from React and into a more web-native, HTML-first approach, please tag me on Mastodon or Threads. We’d love to share further case studies of these modern, dare I say post-React, approaches.

Faster Connectivity !== Faster Websites - Jim Nielsen’s Blog

The bar to overriding browser defaults should be way higher than it is.

Amen!

Standing still - a performance tinker | Trys Mudford

What Trys describes here mirrors my experience too—it really is worth occasionally taking a little time to catch the low-hanging fruit of your site’s web performance (and accessibility):

I’ve shaved nearly half a megabyte off the page size and improved the accessibility along the way. Not bad for an evening of tinkering.

JavaScript Bloat in 2024 @ tonsky.me

This really is a disgusting exlusionary state of affairs.

I hate to be judgy, but I honestly wonder how the people behind some of these decisions can call themselves web developers.

SpeedCurve | The psychology of site speed and human happiness

Tammy takes a deep dive into our brains to examine the psychology of web performance. It opens with this:

If you don’t consider time a crucial usability factor, you’re missing a fundamental aspect of the user experience.

I wish that more UX designers understood that!

Ship Faster by Building Design Systems Slower | Big Medium

Josh mashes up design systems and pace layers, like Mark did a few years back. With this mindset, if your product interface are in sync, that’s not good—either your product is moving too slow or your design system is moving too fast.

The job of the design system team is not to innovate, but to curate. The system should provide answers only for settled solutions: the components and patterns that don’t require innovation because they’ve been solved and now standardized. Answers go into the design system when the questions are no longer interesting—proven out in product. The most exciting design systems are boring.

The Cost Of JavaScript - 2023 - YouTube

A great talk from Addy on just how damaging client-side JavaScript can be to the user experience …and what you can do about it.

Efficiency over performance

I quite like this change of terminology when it comes to making fast websites. After all, performance can sound like a process of addition, whereas efficiency can be a process of subtraction.

The term ‘performance’ brings to mind exotic super-cars suitable only for impractical demonstrations (or ‘performances’). ‘Efficiency’ brings to mind an electric car (or even better, a bicycle), making effective use of limited resources.

Will Serving Real HTML Content Make A Website Faster? Let’s Experiment! - WebPageTest Blog

Spoiler: the answer to the question in the title is a resounding “hell yeah!”

Scott brings receipts.

How To Improve Largest Contentful Paint for Faster Load Times - Calibre

A no-nonsense checklist of good performance advice from Karolina.

The impact of removing jQuery on our web performance - Inside GOV.UK

Following on from that excellent blog post about removing jQuery from gov.uk, here are the performance improvements in charts and numbers.

It may sound like 32 kb of JavaScript is nothing on today’s modern web with quick devices and fast broadband connections. But for a certain cohort of users, it makes a big difference to how they experience GOV.UK.