Design systems: a practical guide

The advice here is unglamorous, which is probably why it gets skipped. This guide covers what design systems actually involves, where it usually goes wrong, and how to tell whether yours is in reasonable shape.

Design decisions are the ones clients feel most confident arguing about, which makes it worth separating taste from evidence early. Nothing below assumes a large team or a large budget — most of it is a decision somebody has to make and then write down.

Why this earns attention

A shared component set stops every page reinventing the same button. The reasoning matters more than the rule, because the rule has exceptions. It is worth deciding this deliberately rather than inheriting whatever the last person set up.

For most businesses the question is not whether this matters but how much of it is worth doing right now. That depends on what you are trying to achieve in the next few months, not on best practice in the abstract. Where this goes wrong is almost never a lack of knowledge.

What good looks like

Tokens for colour, spacing, and type keep decisions consistent. It is worth being explicit about, because assumptions differ quietly. It is the sort of thing that looks like polish right up until it costs you an enquiry.

Consistency is the quiet half of design work: it rarely gets complimented, and its absence is noticed immediately. The version that works in practice is usually less elaborate than the version described in the guides.

The system pays for itself around the third or fourth page. That sounds obvious written down. It is still the thing most often skipped. Doing this properly once is usually cheaper than doing it approximately three times.

A working checklist

If you want a quick read on where you stand, work through this. Anything you cannot answer confidently is where to start.

• A shared component set stops every page reinventing the same button
• Tokens for colour, spacing, and type keep decisions consistent
• The system pays for itself around the third or fourth page
• Someone is named as the owner, not just assumed to be
• There is a date in the calendar to review it again
• The decision and the reasoning behind it are written down somewhere findable
• You could explain the current setup to a new hire in five minutes

Common failure modes

The most common failure is not doing this badly. It is doing it once, during a launch, and never revisiting it. Circumstances move, the setup does not, and the gap widens quietly until something breaks or somebody notices the numbers.

• It was configured during a launch and has not been touched since
• Different people in the business believe different things are true about it
• There is no way to tell whether the last change helped or hurt
• The only person who understands it has left, or is about to

The measurable part of design is whether people can find what they came for and act on it without hesitating. That sounds obvious written down. It is still the thing most often skipped.

How we approach it

On our projects this gets handled during the build rather than added afterwards, because retrofitting it costs several times more than including it. We write down what was decided and why, so the next person to touch it is not guessing.

If you are working with someone else, the questions worth asking are simple: who owns this, how will we know it is working, and what happens when it needs to change?

Making it stick

Pick the single item from the checklist above that would cause the most trouble if it turned out to be wrong. Fix that one, confirm it worked, then move on. Pick the one that would hurt most if it failed, and start there.