When we do front-end development at Clearleft, we’re usually delivering production code, often in the form of a component library. That means our priorities are performance, accessibility, robustness, and other markers of quality when it comes to web development.

Jeremy Keith
Jeremy Keith
one week ago

But every so often, we use the materials of front-end development—HTML, CSS, and JavaScript—to produce something that isn't intended for production. I'm talking about prototyping.

There are plenty of non-code prototyping tools out there, and our designers often reach for them to communicate subtleties like motion design. But when it comes to testing a prototype with real users, it's hard to beat the flexibility of HTML, CSS, and JavaScript. Load it up in a browser and away you go.

We do a lot of design sprints, where time is of the essence. The prototype we produce on the penultimate day of the sprint definitely won't be production quality, but it will be good enough to test.

What's interesting is that—when it comes to prototyping—our usual front-end priorities can and should go out the window. The priority now is speed. If that means sacrificing semantics or performance, then so be it. If I'm building a prototype and I find myself thinking "now, what's the right class name for this component?", then I know I'm in the wrong mindset. That question might be valid for production code, but it's a waste of time for prototypes.

So these two kinds of work require very different attitudes. For production work, quality is key. For prototyping, making something quickly is what matters.

Whereas I would think long and hard about the performance impacts of third-party libraries and frameworks on a public project, I won't give it a second thought when it comes to a prototype. Throw all the JavaScript frameworks and CSS libraries you want at it (although I would argue that in-browser technologies like CSS Grid have made CSS libraries like Bootstrap less necessary, even for prototyping).

Alternating between production projects and prototyping projects can be quite fun, if a little disorienting. It's almost like I have to flip a switch in my brain to change tracks.

When a prototype is successful, works great, and tests well, there's a real temptation to use the prototype code as the basis for the final product. Don't do this! I've made that mistake in the past and it always ends badly. I ended up spending far more time trying to wrangle prototype code to a production level than if I had just started from a clean slate.

Build prototypes to test ideas, designs, interactions, and interfaces ...and then throw the code away. The value of a prototype is in answering questions and testing hypotheses. Don't fall for the sunk cost fallacy when it's time to switch over into production mode.

Of course it should go without saying that you should never, ever release prototype code into production.

And yet...

More and more live sites seem to be built with a prototyping mindset. Weighty JavaScript frameworks are used regardless of appropriateness. Accessibility, if it's even considered at all, is relegated to an afterthought. Fragile architectures are employed that rely on first loading and then executing JavaScript in order to render basic content. Developer experience is prioritised over user experience.

Heydon recently highlighted an article that offered this tip for aspiring web developers:

As for HTML, there’s not much to learn right away and you can kind of learn as you go, but before making your first templates, know the difference between in-line elements like span and how they differ from block ones like div.

That's perfectly reasonable advice ...if you're building a prototype. But if you're building something for public consumption, you have a duty of care to the end users.

This was originally posted on my own site.