sanurb/prd-interview

PRD Interview

Resolve every design decision through a dependency-ordered interview. One branch at a time. No child question asked while the parent is unresolved.

Activation guard: This is a continuation skill. Only run when /tmp/prd-{name}/problem-brief.md exists from a prior prd-discover run. Do not activate independently.

Step 1: Build the Branch Map

Read /tmp/prd-{name}/problem-brief.md. If missing, stop and tell the user to run prd-discover first.

From the problem brief, map decision branches in this fixed order:

| # | Branch | Depends On | Status | |---|--------|-----------|--------| | B1 | Success Criteria | — | open | | B2 | Scope Boundaries & Non-Goals | — | open | | B3 | Solution Approach | B1, B2 | blocked | | B4 | Data Model & State | B3 | blocked | | B5 | Edge Cases & Failure Modes | B3 | blocked | | B6 | Non-Functional Requirements | B2 | blocked | | B7 | Module Design & Testing | B3, B5 | blocked | | B8 | Rollout & Measurement | B1, B3 | blocked |

Show this map to the user before asking the first question.

Step 2: Interview Branch-by-Branch

For each branch (lowest unblocked first), ask the probe questions from references/interview-branches.md.

Per-decision protocol (every decision, no exceptions):

1. Ask ONE question. Wait for the answer.
2. Apply the relevant distinction check:
   • User states a solution → "Is this what to achieve, or how to achieve it?"
   • User states an assumption → "What evidence supports this?"
   • User gives a vague NFR → "What number, at what percentile, under what load?"
   • User gives a vanity metric → "Would a bad implementation still hit this?"
   • User adds scope → Name it, park it, cost it.
3. Record the decision as: decision + rationale + rejected alternative + risk introduced.
4. Confirm wording with user before moving to the next question.

After resolving a branch, update its status to decided and unblock dependents.

Step 3: Produce the Decision Ledger

When all branches are decided or deferred-with-owner, write to /tmp/prd-{name}/decision-ledger.md.

Copy the template from assets/decision-ledger-template.md and fill every section from the interview.

Non-Negotiable Acceptance Criteria

The decision ledger is NOT complete unless ALL of these are true:

• [ ] Every branch is decided or deferred-with-owner — no branch left open
• [ ] Every deferred decision has an owner, a revisit trigger, and what it blocks
• [ ] B1 has at least one primary metric that passes the vanity test
• [ ] B2 has at least 2 explicit non-goals
• [ ] B3 describes outcomes, not implementation — zero UI prescriptions
• [ ] B5 has at least 3 failure/degradation scenarios
• [ ] B6 has no adjectives without numbers
• [ ] Every assumption is labeled as an assumption, never encoded as a decided fact
• [ ] User has confirmed: "This reflects our shared understanding"

Output

• Artifact: /tmp/prd-{name}/decision-ledger.md
• Next skill: prd-draft