A design system is mostly a promise about what you won't do

We built a design system with no designer on staff.

This sounds like the setup for a disaster story. It isn't. It's the reason the system works.

What a design system actually is

Most design systems are described as collections of components — buttons, cards, type scales, spacing tokens. That framing is technically correct and practically useless.

A design system is a set of decisions you've already made. Its value is not in what it provides. It is in what it prevents.

The seven things ours refuses

1. More than one typeface family. We use IBM Plex. That's it.
2. More than three accent colours active at once.
3. A button style that isn't in the system.
4. A heading weight below 200 or above 500.
5. A line-height below 1.05 on display text.
6. A border-radius that isn't on the four-value scale.
7. Any animation with a duration above 600ms.

These refusals were all responses to specific decisions that made the product worse. The system is, in that sense, a record of our mistakes.

Running design without a designer

The system means that a developer making a new page has a finite set of correct choices. There is no blank canvas. The canvas is already primed.

That's the point. Taste at scale is a systems problem, not a hiring problem.