Tags: service

If you’re building software, it’s generally a good idea to avoid the Not-Invented-Here syndrome. This is when you insist on writing absolutely everything from scratch even if it would make more sense to use a third-party provider.

Need your app to take payments? Don’t try to become your own payment provider—use an existing provider instead.

Need your app to send email? Don’t try to code all that up yourself—just use an existing service.

This same thinking seems to apply to JavaScript libraries too. If you don’t use a library or framework, you’ll just end up writing your own library or framework instead, right?

Except that’s not the way that JavaScript frameworks work. At least not any more.

There was a time when JavaScript libraries really did abstract away browser differences that you probably didn’t want to deal with yourself. In the early days of jQuery—before querySelector existed—trying to work with the DOM could be a real pain. Libraries like jQuery helped avoid that pain.

Maybe it was even true in the early days of Angular and React. If you were trying to handle navigations yourself, it probably made sense to use a framework.

But that’s not the case any more, and hasn’t been for quite a while.

These days, client-side JavaScript frameworks don’t abstract away the underlying platform, they instead try to be an alternative. In fact, if you attempt to use web platform features, your JavaScript framework will often get in the way. You have to wait until your framework of choice supports a feature like view transitions before you get to use it.

This is nuts. Developers are choosing to use tools that actively get in the way of the web platform.

I think that most developers have the mental model of JavaScript frameworks completely backwards. They believe that the framework saves them time and effort (just like a payment provider or an email service). Instead these frameworks are simply limiting the possibility space of what you can do in web browsers today.

When you use a JavaScript framework, that isn’t the end of your work, it’s just the beginning. You still have to write your own code that makes use of that framework. Except now your code is restricted to only what the framework can do.

And yet most developers still believe that using a JavaScript framework somehow enables them to do more.

Jim Nielsen has a great framing on this. JavaScript libraries aren’t like payment providers or email services. Rather, it’s the features built into web browsers today that are like these third-party providers. When you use these features, you’re benefiting from all the work that the browser makers have put into making them as efficient as possible:

Browser makers have teams of people who, day-in and day-out, are spending lots of time developing and optimizing new their offerings.

So if you leverage what they offer you, that gives you an advantage because you don’t have to build it yourself.

Want to do nifty page transitions? Don’t use a library. Use view transitions.

Want to animate parts of the page as the user scrolls? Don’t use a library. Use scroll-driven animations.

Want to make something happen when the user clicks? Don’t use a library. For the love of all that is holy, just use a button.

If you agree that using a button makes more sense than using a div, then I encourage you to apply the same thinking to everything else your app needs to do.

Take advantage of all the wonderful things you can do in web browsers today. If instead you decide to use a JavaScript framework, you’re basically inventing from scratch.

Except now all of your users pay the price because they’re the ones who have to download the JavaScript framework when they use your app.

I’m very happy to announce that the one and only Jake Jaffa-The-Cake Archibald will be speaking at Web Day Out!

Given the agenda for this event, I think you’ll agree that Jake is a perfect fit. He’s been at the forefront of championing user-centred web standards, writing specs and shipping features in browsers.

Along the way he’s also created two valuable performance tools that I use all the time: SVGOMG and Squoosh, which has a permanent place in my dock—if you need to compress images, I highly recommend adding this progressive web app to your desktop.

He’s the man behind service workers and view transitions—two of the most important features for making websites first-class citizens on any device.

So what will he talk about at Web Day Out? Image formats? Offline functionality? Smooth animations? Something else entirely?

All will be revealed soon. In the meantime, grab yourself a ticket to Web Day Out—it’s just £225+VAT—and I’ll see you in Brighton on Thursday, 12 March 2026!

The Session has been online for over 20 years. When you maintain a site for that long, you don’t want to be relying on third parties—it’s only a matter of time until they’re no longer around.

Some third party APIs are unavoidable. The Session has maps for sessions and other events. When people add a new entry, they provide the address but then I need to get the latitude and longitude. So I have to use a third-party geocoding API.

My code is like a lesson in paranoia: I’ve built in the option to switch between multiple geocoding providers. When one of them inevitably starts enshittifying their service, I can quickly move on to another. It’s like having a “go bag” for geocoding.

Things are better on the client side. I’m using other people’s JavaScript libraries—like the brilliant abcjs—but at least I can self-host them.

I’m using Leaflet for embedding maps. It’s a great little library built on top of Open Street Map data.

A little while back I linked to a new project called OpenFreeMap. It’s a mapping provider where you even have the option of hosting the tiles yourself!

For now, I’m not self-hosting my map tiles (yet!), but I did want to switch to OpenFreeMap’s tiles. They’re vector-based rather than bitmap, so they’re lovely and crisp.

But there’s an issue.

I can use OpenFreeMap with Leaflet, but to do that I also have to use the MapLibre GL library. But whereas Leaflet is 148K of JavaScript, MapLibre GL is 800K! Yowzers!

That’s mahoosive by the standards of The Session’s performance budget. I’m not sure the loveliness of the vector maps is worth increasing the JavaScript payload by so much.

But this doesn’t have to be an either/or decision. I can use progressive enhancement to get the best of both worlds.

If you land straight on a map page on The Session for the first time, you’ll get the old-fashioned bitmap map tiles. There’s no MapLibre code.

But if you browse around The Session and then arrive on a map page, you’ll get the lovely vector maps.

Here’s what’s happening…

The maps are embedded using an HTML web component called embed-map. The fallback is a static image between the opening and closing tags. The web component then loads up Leaflet.

Here’s where the enhancement comes in. When the web component is initiated (in its connectedCallback method), it uses the Cache API to see if MapLibre has been stored in a cache. If it has, it loads that library:

caches.match('/path/to/maplibre-gl.js')
.then( responseFromCache => {
    if (responseFromCache) {
        // load maplibre-gl.js
    }
});

Then when it comes to drawing the map, I can check for the existence of the maplibreGL object. If it exists, I can use OpenFreeMap tiles. Otherwise I use the old Leaflet tiles.

But how does the MapLibre library end up in a cache? That’s thanks to the service worker script.

During the service worker’s install event, I give it a list of static files to cache: CSS, JavaScript, and so on. That includes third-party libraries like abcjs, Leaflet, and now MapLibre GL.

Crucially this caching happens off the main thread. It happens in the background and it won’t slow down the loading of whatever page is currently being displayed.

That’s it. If the service worker installation works as planned, you’ll get the nice new vector maps. If anything goes wrong, you’ll get the older version.

By the way, it’s always a good idea to use a service worker and the Cache API to store your JavaScript files. As you know, JavaScript is unduly expensive to performance; not only does the JavaScript file have to be downloaded, it then has to be parsed and compiled. But JavaScript stored in a cache during a service worker’s install event is already parsed and compiled.

I wrote a book about service workers. It’s called Going Offline. It was first published by A Book Apart in 2018. Now it’s available to read for free online.

If you want you can read the book as a PDF, an ePub, or .mobi, but I recommend reading it in your browser.

Needless to say the web book works offline. Once you go to goingoffline.adactio.com you can add it to the homescreen of your mobile device or add it to the dock on your Mac. After that, you won’t need a network connection.

The book is free to read. Properly free. Not the kind of “free” where you have to supply an email address first. Why would I make you go to the trouble of generating a burner email account?

The site has no analytics. No tracking. No third-party scripts of any kind whatsover. By complete coincidence, the site is fast. Funny that.

For the styling of this web book, I tweaked the stylesheet I used for HTML5 For Web Designers. I updated it a little bit to use logical properties, some fluid typography and view transitions.

In the process of converting the book to HTML, I got reaquainted with what I had written almost seven years ago. It was kind of fun to approach it afresh. I think it stands up pretty darn well.

Ethan wrote about his feelings when he put two of his books online, illustrated by that amazing photo that always gives me the feels:

I’ll miss those days, but I’m just glad these books are still here. They’re just different than they used to be. I suppose I am too.

Anyway, if you’re interested in making your website work offline, have a read of Going Offline. Enjoy!

Reckoning: Part 1 — The Landscape - Infrequently Noted

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:

1. The Landscape
2. Object Lesson
3. Caprock
4. The Way Out

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”.

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.

minimum interesting service worker

An interesting idea from Tantek for an offline page that links off to an archived copy of the URL you’re trying to reach—useful for when you’re site goes down (though not for when the user’s internet connection is down).

After I wrote positively about the speculation rules API I got an email from David Cizek with some legitimate concerns. He said:

I think that this kind of feature is not good, because someone else (web publisher) decides that I (my connection, browser, device) have to do work that very often is not needed. All that blurred by blackbox algorithm in the browser.

That’s fair. My hope is that the user will indeed get more say, whether that’s at the level of the browser or the operating system. I’m thinking of a prefers-reduced-data setting, much like prefers-color-scheme or prefers-reduced-motion.

But this issue isn’t something new with speculation rules. We’ve already got service workers, which allow the site author to unilaterally declare that a bunch of pages should be downloaded.

I’m doing that for Resilient Web Design—when you visit the home page, a service worker downloads the whole site. I can justify that decision to myself because the entire site is still smaller in size than one article from Wired or the New York Times. But still, is it right that I get to make that call?

So I’m very much in favour of browsers acting as true user agents—doing what’s best for the user, even in situations where that conflicts with the wishes of a site owner.

Going back to speculation rules, David asked:

Do we really need this kind of (easily turned to evil) enhancement in the current state of (web) affairs?

That question could be asked of many web technologies.

There’s always going to be a tension with any powerful browser feature. The more power it provides, the more it can be abused. Animations, service workers, speculation rules—these are all things that can be used to improve websites or they can be abused to do things the user never asked for.

Or take the elephant in the room: JavaScript.

Right now, a site owner can link to a JavaScript file that’s tens of megabytes in size, and the browser has no alternative but to download it. I’d love it if users could specify a limit. I’d love it even more if browsers shipped with a default limit, especially if that limit is related to the device and network.

I don’t think speculation rules will be abused nearly as much as client-side JavaScript is already abused.

I’m at day two of Indie Web Camp Brighton.

Day one was excellent. It was really hard to choose which sessions to go to because they all sounded interesting. That’s a good problem to have.

I ended up participating in:

• a session on POSSE,
• a session on NFC tags,
• a session on writing, and
• a session on testing your website that was hosted by Ros

In that testing session I shared some of the bookmarklets I use regularly.

Bookmarklets? They’re bookmarks that sit in the toolbar of your desktop browser. Just like any other bookmark, they’re links. The difference is that these links begin with javascript: rather than http. That means you can put programmatic instructions inside the link. Click the bookmark and the JavaScript gets executed.

In my mind, there are two different approaches to making a bookmarklet. One kind of bookmarklet contains lots of clever JavaScript—that’s where the smart stuff happens. The other kind of bookmarklet is deliberately dumb. All they do is take the URL of the current page and pass it to another service—that’s where the smart stuff happens.

I like that second kind of bookmarklet.

Here are some bookmarklets I’ve made. You can drag any of them up to the toolbar of your browser. Or you could create a folder called, say, “bookmarklets”, and drag these links up there.

Validation: This bookmarklet will validate the HTML of whatever page you’re on.

Validate HTML

Carbon: This bookmarklet will run the domain through the website carbon calculator.

Calculate carbon

Accessibility: This bookmarklet will run the current page through the Website Accessibility Evaluation Tools.

WAVE

Performance: This bookmarklet will take the current page and it run it through PageSpeed Insights, which includes a Lighthouse test.

PageSpeed

HTTPS: This bookmarklet will run your site through the SSL checker from SSL Labs.

SSL Report

Headers: This bookmarklet will test the security headers on your website.

Security Headers

Drag any of those links to your browser’s toolbar to “install” them. If you don’t like one, you can delete it the same way you can delete any other bookmark.

Service Design Breakfast Club meet-up for UK service designers

Service designers of Brighton!

We meet for 1–1½ hours from 8.30am on the first Thursday of every month at Clearleft’s studio in Brighton.

as days pass by — Farmbound, or how I built an app in 2022

Stuart writes up the process up making a mobile game as a web app—not a native app. The Wordle effect reverberates.

It’s a web app. Works for everyone. And I thought it would be useful to explain why it is, why I think that’s the way to do things, and some of the interesting parts of building an app for everyone to play which is delivered over the web rather than via app stores and downloads.

It’s Time to Build a Progressive Web App. Here’s How – The New Stack

Much as I appreciate the optimism of this evaluation, I don’t hold out much hope that people’s expectations are going to change any time soon:

Indeed, when given a choice, users will opt for the [native] app version of a platform because it’s been considered the gold standard for reliability. With progressive web apps (PWAs), that assumption is about to change.

Nonetheless, this is a level-headed look at what a progressive web app is, mercifully free of hand-waving:

• App is served through HTTPS.
• App has a web app manifest with at least one icon. (We’ll talk more about the manifest shortly.)
• App has a registered service worker with a fetch event handler. (More on this later too.)

I’ve noticed a strange mindset amongst front-end/full-stack developers. At least it seems strange to me. But maybe I’m the one with the strange mindset and everyone else knows something I don’t.

It’s to do with trust and suspicion.

I’ve made no secret of the fact that I’m suspicious of third-party code and dependencies in general. Every dependency you add to a project is one more potential single point of failure. You have to trust that the strangers who wrote that code knew what they were doing. I’m still somewhat flabbergasted that developers regularly add dependencies—via npm or yarn or whatever—that then pull in even more dependencies, all while assuming good faith and competence on the part of every person involved.

It’s a touching expression of faith in your fellow humans, but I’m not keen on the idea of faith-based development.

I’m much more trusting of native browser features—HTML elements, CSS features, and JavaScript APIs. They’re not always perfect, but a lot of thought goes into their development. By the time they land in browsers, a whole lot of smart people have kicked the tyres and considered many different angles. As a bonus, I don’t need to install them. Even better, end users don’t need to install them.

And yet, the mindset I’ve noticed is that many developers are suspicious of browser features but trusting of third-party libraries.

When I write and talk about using service workers, I often come across scepticism from developers about writing the service worker code. “Is there a library I can use?” they ask. “Well, yes” I reply, “but then you’ve got to understand the library, and the time it takes you to do that could be spent understanding the native code.” So even though a library might not offer any new functionality—just a different idion—many developers are more likely to trust the third-party library than they are to trust the underlying code that the third-party library is abstracting!

Developers are more likely to trust, say, Bootstrap than they are to trust CSS grid or custom properties. Developers are more likely to trust React than they are to trust web components.

On the one hand, I get it. Bootstrap and React are very popular. That popularity speaks volumes. If lots of people use a technology, it must be a safe bet, right?

But if we’re talking about popularity, every single browser today ships with support for features like grid, custom properties, service workers and web components. No third-party framework can even come close to that install base.

And the fact that these technologies have shipped in stable browsers means they’re vetted. They’ve been through a rigourous testing phase. They’ve effectively got a seal of approval from each individual browser maker. To me, that seems like a much bigger signal of trustworthiness than the popularity of a third-party library or framework.

So I’m kind of confused by this prevalent mindset of trusting third-party code more than built-in browser features.

Is it because of the job market? When recruiters are looking for developers, their laundry list is usually third-party technologies: React, Vue, Bootstrap, etc. It’s rare to find a job ad that lists native browser technologies: flexbox, grid, service workers, web components.

I would love it if someone could explain why they avoid native browser features but use third-party code.

Until then, I shall remain perplexed.

Streets Series’ Articles - DEV Community 👩‍💻👨‍💻

This is a really excellent four-part series on web performance that really dives into the technical details and asks all the right questions:

1. Making the world’s fastest website, and other mistakes
2. The weirdly obscure art of Streamed HTML
3. Speed Needs Design, or: You can’t delight users you’ve annoyed
4. Routing: I’m not smart enough for a SPA

How to make MPAs that are as fast as SPAs | Go Make Things

The headline is a little misleading because if you follow this advice, your multi-page apps will be much much faster than single page apps, especially when you include that initial page load of a single page app.

Here’s a quick high-level summary of what I do…

1. Serve pre-rendered, mostly static HTML.
2. Inline everything, including CSS and JavaScript.
3. Use mostly platform-native JavaScript, and as little of it as possible.
4. Minify and gzip all the things.
5. Lean heavily on service workers.

That’s an excellent recipe for success right there!

Add a Service Worker to Your Site | CSS-Tricks - CSS-Tricks

Damn, I wish I had thought of giving this answer to the prompt, “What is one thing people can do to make their website better?”

If you do nothing else, this will be a huge boost to your site in 2022.

Chris’s piece is a self-contained tutorial!

Serve folder for web development

This is a very nifty use of a service worker—choose a local folder that you want to navigate using HTTP rather than the file system.

Getting Started with PWAs [Workshop]

The slides from Aaron’s workshop at today’s PWA Summit. I really like the idea of checking navigator.connection.downlink and navigator.connection.saveData inside a service worker to serve different or fewer assets!

11ty/api-indieweb-avatar: Return an optimized avatar image from a domain name input.

Here’s a nifty little service from Zach: pass in a URL and it returns an image of the site’s icon.

Here’s mine.

Think of it as the indie web alternative to showing Twitter avatars.

Let’s talk about failure

Denise shares a cautionary tale of service design gone wrong.