What it is
Short list of behaviors and decision heuristics that encode product culture. Cited in reviews to settle debates without re-litigating values.
Concrete example
“Bias to simplicity,” “Build for 10x, not 10%,” each with a one-sentence explanation used in reviews.
When to use it
When the team keeps re-debating the same trade-offs, or when new hires can't infer “how we decide” from existing artifacts.
What Product Joi delivers
5–7 product principles: short rule, one-paragraph rationale, examples of how each principle has been applied, and counter-examples.
Turnaround
48 hours
Format
Decision-first doc
Reviewed by
Senior product lead