From Prototype to PRD: Document Decisions, Not Screens

Many PMs treat the PRD as a blueprint: “here’s the UI, build it.” That’s brittle. Screens change. Decisions should not.

A better approach: the PRD is a decision record.

What to document:

1) The user goal and success conditions

• persona + moment
• job-to-be-done
• success metrics (behavior + outcome) This keeps the team anchored when details shift.

2) The chosen approach and tradeoffs

Write:

• what direction we chose
• why we chose it
• what we rejected
• what we’re trading away (and why it’s acceptable)

This prevents re-litigating.

3) The key flow (not every pixel)

Use:

• a flow diagram
• key states (empty, loading, error)
• decision points Avoid pixel-level instructions unless they’re true constraints.

4) Risks and mitigations

Call out:

• usability risks (where users struggled in testing)
• trust risks (what they need to believe)
• feasibility risks (what eng flagged) And the plan to mitigate (instrumentation, rollout, follow-up).

5) Acceptance criteria that reflect outcomes

Instead of “button is blue,” use:

• “Primary action is visible without scrolling”
• “User can undo automation”
• “System explains data source/freshness” These are durable and protect quality.

Interview line:

“My PRDs don’t prescribe screens. They capture decisions, tradeoffs, risks, and success conditions. Design stays flexible; the team stays aligned.”

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