design-synthesis

name	design-synthesis
type	simple
depth	extended
description	Synthesizes research findings into design decisions via codebase investigation. Use when (1) translating research into implementation approaches, (2) selecting between design alternatives, (3) executing after /research or deep-research, or (4) preparing input for /plan phase.

[H1][DESIGN-SYNTHESIS]

Dictum: Design decisions require grounded context before implementation.

Synthesize research findings into design decisions via light codebase investigation.

Workflow:

1. §INGEST — Load research artifact, parse original request
2. §SCAN — Light codebase investigation via parallel-dispatch (3-4 agents)
3. §EXPLORE — Generate 2-3 approaches with trade-offs
4. §SELECT — Commit to best approach with rationale
5. §OUTPUT — Structured design document

Dependencies:

• parallel-dispatch — Agent orchestration for codebase scan
• Research artifact — External findings from deep-research

Input:

• Research: Path to research artifact (research_{slug}.md)
• Request: Original user request/intent

---

[1][INGEST]

Dictum: Grounded context prevents speculative design.

Load and parse inputs:

[INDEX]	Source	Extract
[1]	Research file	Findings, confidence levels, key sources
[2]	Request	Intent, scope boundaries, success criteria

Parse research structure:

• ## [1][FINDINGS] → Domain knowledge by category
• ## [2][CONFIDENCE] → High/Medium/Low ratings
• ## [3][SOURCES] → Attribution for decisions

[IMPORTANT]:

• [ALWAYS] Extract high-confidence findings as primary input.
• [ALWAYS] Note low-confidence areas as design risks.
• [NEVER] Proceed without understanding request intent.

---

[2][SCAN]

Dictum: Pattern awareness prevents reinvention.

Dispatch 3-4 agents via parallel-dispatch for codebase context.

Agent Assignment:

[INDEX]	[AGENT]	[SCOPE]	[RETURNS]
[1]	Patterns	Similar implementations in codebase	Conventions, reusable patterns, prior art
[2]	Constraints	Project rules, architecture limits	Hard boundaries, style requirements
[3]	Interfaces	Entry/exit points for feature area	Touch points, consumers, integration surface

Agent Prompt Template:

Scope: [Specific investigation area]
Objective: Surface [patterns|constraints|interfaces] relevant to: [request summary]
Output: Bullet list of findings with file paths
Context: Research indicates: [key findings summary]
Exclusions: Do NOT analyze implementation details or specific file contents

[CRITICAL]:

• [ALWAYS] Dispatch ALL agents in ONE message block.
• [ALWAYS] Scope to patterns/constraints/interfaces—NOT implementation.
• [NEVER] Deep-dive into file contents—that's plan's job.

---

[3][EXPLORE]

Dictum: Comparison reveals optimal trade-offs.

Generate 2-3 distinct approaches from research + scan findings.

Per Approach:

[INDEX]	Aspect	Content
[1]	Strategy	High-level implementation direction
[2]	Alignment	How it leverages research findings
[3]	Patterns	Which codebase conventions it follows
[4]	Trade-offs	Pros and cons

Approach Generation Criteria:

• Approach A: Most aligned with existing patterns (conservative)
• Approach B: Best leverage of research findings (optimal)
• Approach C: Simplest implementation path (minimal) — optional

[IMPORTANT]:

• [ALWAYS] Ground approaches in scan findings—no speculation.
• [ALWAYS] Include trade-off analysis per approach.
• [ALWAYS] Apply YAGNI—cut unnecessary scope from all approaches.
• [NEVER] Generate approaches without codebase evidence.

---

[4][SELECT]

Dictum: Committed direction enables focused planning.

Select best approach via weighted criteria:

[INDEX]	Criterion	Weight	Evaluation
[1]	Pattern alignment	High	Matches existing codebase conventions
[2]	Research support	High	Backed by high-confidence findings
[3]	Simplicity	Medium	Minimal moving parts
[4]	Risk profile	Medium	Low-confidence areas minimized

Selection Output:

• Selected approach name
• Primary rationale (1-2 sentences)
• Key trade-off accepted

[CRITICAL]:

• [ALWAYS] Commit to ONE approach—no hedging.
• [ALWAYS] Document trade-off accepted.
• [NEVER] Defer selection to downstream phases.

---

[5][OUTPUT]

Dictum: Downstream consumers require predictable structure.

Produce brainstorm.md with structure:

# [H1][DESIGN]: [Title]
>**Dictum:** *[Build target—refined from request]*

<br>

**Research Summary:** [Key findings relevant to design]

---
## [1][APPROACHES]

### [1.1][APPROACH_A]: [Name]

| [INDEX] | [ASPECT]  | [DETAIL]                        |
| :-----: | --------- | ------------------------------- |
|   [1]   | Strategy  | [High-level direction]          |
|   [2]   | Alignment | [Research findings leveraged]   |
|   [3]   | Patterns  | [Codebase conventions followed] |
|   [4]   | Pros      | [Benefits]                      |
|   [5]   | Cons      | [Drawbacks]                     |

---
### [1.2][APPROACH_B]: [Name]

| [INDEX] | [ASPECT]  | [DETAIL]                        |
| :-----: | --------- | ------------------------------- |
|   [1]   | Strategy  | [High-level direction]          |
|   [2]   | Alignment | [Research findings leveraged]   |
|   [3]   | Patterns  | [Codebase conventions followed] |
|   [4]   | Pros      | [Benefits]                      |
|   [5]   | Cons      | [Drawbacks]                     |

---
## [2][SELECTED_APPROACH]

| [INDEX] | [KEY]              | [VALUE]                |
| :-----: | ------------------ | ---------------------- |
|   [1]   | Choice             | [Approach name]        |
|   [2]   | Rationale          | [Why this approach]    |
|   [3]   | Trade-off Accepted | [What we're giving up] |

---
## [3][DESIGN_CONSTRAINTS]

| [INDEX] | [CONSTRAINT]    | [SOURCE]        |
| :-----: | --------------- | --------------- |
|   [1]   | [Hard boundary] | [Codebase scan] |
|   [2]   | ...             | ...             |

---
## [4][KEY_DECISIONS]

| [INDEX] | [DECISION]      | [CHOICE]          | [RATIONALE] |
| :-----: | --------------- | ----------------- | ----------- |
|   [1]   | [Design choice] | [Selected option] | [Why]       |
|   [2]   | [Design choice] | [Selected option] | [Why]       |

[CRITICAL]:

• [ALWAYS] Include all sections—downstream depends on structure.
• [ALWAYS] Table format for approaches and decisions.
• [NEVER] Prose paragraphs—tables and lists only.

---

[6][VALIDATION]

Dictum: Incomplete synthesis cascades errors downstream.

[VERIFY]:

• Ingest: Research parsed, request intent extracted
• Scan: 3-4 agents dispatched in ONE message
• Explore: 2-3 approaches with trade-offs generated
• Select: ONE approach committed with rationale
• Output: All sections present, table format used
• YAGNI: Unnecessary scope cut from all approaches