Rules, .cursorrules and standardization

Rules are the SA's single most impactful lever, because they turn tribal knowledge that lives in three senior engineers' heads into a standard the model follows for everyone.

Left to defaults, every developer gets slightly different output: different patterns, different libraries, different opinions on error handling. That variance is fine for one person experimenting. Across a 300-engineer org it's chaos and it's the thing a VP of Engineering worries about when they hear "we're rolling out AI coding."

Rules are how you answer that worry. They are persistent instructions that get injected into the model's context so its behavior conforms to your conventions, your stack and your guardrails.