Design systems have a reputation for being heavyweight. For a small team, that reputation is a trap — a lightweight system pays for itself almost immediately.
Start with tokens: colors, spacing, and typography defined once and reused everywhere. This alone eliminates most visual drift.
Then build a small set of well-made components and document their states. You don't need every component on day one — just the ones you use constantly.
Treat it as a living thing. The system should grow with the product, not freeze it. The goal is speed and consistency, not bureaucracy.