--- name: multi-persona-review (parallax) description: Generalized architecture for multi-persona parallel artifact review — parallel isolated personas + shared output protocol + neutral synthesizer. The domain-agnostic, IP-stripped pattern named "parallax" for FH; embodied as sim-conductor Step 1.5. Use when designing or explaining structured multi-viewpoint review (code, spec, design, plan). type: reference tags: [pattern, multi-persona, review, parallax, sim-conductor, verify-axis] --- # Multi-Persona Parallel Review — the `parallax` pattern > **parallax**: depth — the hidden, the omitted — is only perceivable from multiple viewpoints. One > standpoint is flat; the shift *between* standpoints reveals what a single seat cannot. The name is the > thesis: structured multi-standpoint coverage finds categorically more than any one viewpoint. **Provenance**: generalized and domain-stripped from a field marketplace implementation (`deep-insight`, a company-internal term — not adopted here). The domain-agnostic *architecture* is portable; the domain-specific personas were field extensions and are excluded. In FH this pattern is a **mode of `sim-conductor`** (Step 1.5), not a separate skill — see `asset-placement-gate` verdict (2026-06-06): it overlaps sim-conductor ~80–90%, so the distinctive patterns were absorbed, not forked. ## The architecture (6 + 1 patterns) 1. **Parallel isolated persona spawn** — N personas run as parallel agents (`Task(subagent_type=…)` / parallel Agents), each in its own context, no inter-agent communication. Isolation is mechanical: it lets each persona reach an independent verdict, which is what makes cross-persona agreement meaningful. 2. **Shared output protocol (constitution)** — every persona, whatever its lens, emits the same shape: ``` ### Strengths (0–3, from this persona's viewpoint) ### Concerns Critical — compile/runtime failure · clear logic error · data corruption · security leak Important — significant user/service impact in a plausible scenario Suggestion — optional improvement (each: [file:line or quoted span] one-line summary — rationale) ### Open questions (0–3 needed for a decision) ### Absence check (outside-vantage personas: what does the artifact FAIL to specify that this standpoint needs — discoverability, undocumented contract, unstated assumption?) ``` 3. **Neutral synthesizer** — a NON-persona aggregator that injects no opinion: never a conclusion no persona stated · preserve attribution (who said what) · priority labels verbatim · no forced consensus or forced conflict. It reports Common opinions (2+ agree) and Conflicts (A vs B, each with rationale). 4. **Persona taxonomy (group aliases)** — `dev` (fe/be/…), `biz` (pm/designer/…), `review` (qa/compliance/devil-advocate), `user` (newcomer/power-user), `all`. Sourced, not hardcoded. 5. **FP judgment discipline** — only escalate when confident. Never escalate: pre-existing issues · style without a quotable rule · linter-catchable · speculative · subjective (→ Suggestion). *If not confident, do not mark it* — false positives erode reviewer trust. 6. **Devil's advocate as a structural member** — not a special case; a standard member of `review`. Every objection carries a rationale (no contrarianism for its own sake); the faster others converge, the harder it hunts the weak point. 7. **External-harness persona sourcing** (FH addition) — a lens may be sourced from an installed *sibling harness*, not only the built-in palette: e.g. gstack `/review` (staff-engineer), `/cso` (security-officer), `/qa` (QA-lead). The orchestrator runs FH; the sibling supplies the specialist lens. Isomorphic to `steel-quench` Step 0.4 (Specialized Reviewer Discovery) + Wave 5 (external CLIs). ## The two-layer severity (why it's required, not redundant) Per-persona `Critical/Important/Suggestion` (each persona's own judgment in isolation) → synthesizer triages to `M/S/R` (cross-persona). An isolated persona **cannot** assign `S = found by 3+ personas` — that depends on agreement it never sees. So the per-persona → synthesized split is *required by isolation*, not duplicate vocabulary. ## What this pattern's value actually IS (honest, from the R9 experiment arc) Established by controlled experiment (companion-store `RESULT9`, codex, capability-controlled, 2026-06-06): - **It is NOT de-biasing.** Ownership had ≈ zero effect (a model self-reviewing blunt = an outsider blunt). It is NOT "seeing what the author structurally can't": when explicitly asked, an author finds their own omissions about as well as an outsider (clean replication refuted the "non-self-administrable" claim). - **What is real**: the gradient **`blunt < single-rubric < multi-persona`** — structured multi-standpoint coverage finds categorically more (a single-flaw prompt missed SSRF; a single rubric missed the consumer-contract axis a newcomer surfaces). Different standpoints make different issues *visible*. - **So the value is**: **pure rubric/standpoint supply + routine enforcement** — the pattern assembles and *routinely runs* the structured multi-standpoint rubric (including the omission/absence check) that a builder would not assemble or run on themselves. **Fully copyable utility, zero cognitive-moat.** Isolation's role is mechanical (independent verdicts → honest cross-persona triage + decorrelation), not cognitive. This framing is falsifiable and matches FH's utility-not-moat positioning: the personas are a copyable marketplace; the marginal value is making the structured sweep routine, not exclusivity. ## Where it lives in FH - **Operational home**: `sim-conductor` Step 1.5 (Persona Output Protocol + Neutral Synthesizer). Area D (artifact validation) is the focused multi-persona review entry point. - **Sourcing kinship**: `steel-quench` Step 0.4 + Wave 5 (external reviewer/CLI discovery). - **6-axis**: a validated pattern for **Axis 5 (Verify)** — structured multi-viewpoint review of a near-complete artifact, complementary to steel-quench (adversarial hardening) and phantom-quench (source grounding).