A design system is a contract between design and engineering. Keep it small, keep it used, keep it honest.
Every team we meet has a version of the same problem: plenty of activity, very little certainty about which parts of it are working. The instinct is to add another channel. The better move is almost always to sharpen what you already have and measure it properly.
Start with the decision
Before a campaign, a redesign or a rebrand, write down the decision a customer has to make and the moment they make it. Everything downstream — the words, the layout, the channel mix — is in service of that moment. If a deliverable doesn't help, it's decoration.
Make it measurable
Pick one number per quarter. Not five. Agree what counts as a conversion, instrument it once, and resist the urge to redefine it halfway through. The discipline is boring and it's the reason compounding happens.
That's the whole method, really: decide what matters, build it with care, and check honestly whether it worked.