Brainstorming

Clarify WHAT to build before HOW to build it.

Hard Gate

No implementation until the design is approved. Brainstorming produces a design document, not code. Do not invoke implementation skills, write production code, or create files outside docs/brainstorms/ until the user explicitly approves the design and moves to planning.

Core Process

Phase 0: Assess and Ground

Before diving into questions, do two things:

Ground in the codebase (when applicable). If the brainstorm relates to existing code, read the relevant modules, patterns, and constraints before generating options. This prevents suggesting approaches that conflict with the actual architecture. Skip for purely abstract brainstorms (tech choices, product direction) where no codebase context applies.

Right-size the artifact. Match ceremony to problem size. If the brainstorm resolves in 3 messages, don't force a formal design doc -- a summary comment is enough. If it spans multiple sessions and touches architecture, write the full Phase 3 doc. No ceremony tax.

Assess whether brainstorming is needed:

Signals that requirements are clear:

• User provided specific acceptance criteria
• User referenced existing patterns to follow
• User described exact behavior expected
• Scope is constrained and well-defined

Signals that brainstorming is needed:

• User used vague terms ("make it better", "add something like")
• Multiple reasonable interpretations exist
• Trade-offs haven't been discussed
• User seems unsure about the approach
• User described a solution ("build a dashboard") instead of a problem
• Request spans multiple independent subsystems -- decompose first (see Scope Decomposition below)

If requirements are clear, suggest: "Your requirements seem clear. Consider proceeding directly to planning or implementation."

Scope Decomposition Gate

If the request describes multiple independent subsystems (e.g., "build a platform with chat, file storage, billing, and analytics"), flag this immediately. Don't spend questions refining details of a project that needs decomposition first.

1. Identify the independent pieces and how they relate
2. Determine build order (dependencies, shared infrastructure first)
3. Brainstorm the first sub-project through the normal Phase 1-3 flow
4. Each sub-project gets its own spec -> plan -> implementation cycle

Phase 1: Understand the Idea

User context calibration (before diving into the idea):

Read signals from the user's first message to calibrate communication register:

• Vocabulary: Are they using technical terms (API, schema, migration) or describing experiences (it's slow, it breaks when...)?
• Framing: Are they describing a solution ("build a dashboard") or a problem ("I can't see what's happening")?
• References: Are they pointing to code, files, and patterns, or to analogies and comparisons ("something like Notion")?

Adjust question style accordingly. Technical users get architecture-level probing. Non-technical users get experience-level probing. Don't ask about this calibration -- just do it. If signals are ambiguous, default to the vocabulary the user is already using.

Explore project context first: Before asking questions, read existing files, docs, and recent commits related to the idea. Understanding what exists prevents asking questions the codebase already answers and grounds the conversation in reality.

Ask questions one at a time by default. When probing a single dimension (e.g., data model, auth flow), 2-3 related questions together is acceptable -- see Question Clustering below.

Question Techniques:

1. Prefer multiple choice when natural options exist

   • Good: "Should the notification be: (a) email only, (b) in-app only, or (c) both?"
   • Avoid: "How should users be notified?"

2. Start broad, then narrow

   • First: What is the core purpose?
   • Then: Who are the users?
   • Finally: What constraints exist?

3. Validate assumptions explicitly

   • "I'm assuming users will be logged in. Is that correct?"

4. Ask about success criteria early

   • "How will you know this feature is working well?"

Key Topics to Explore:

Topic	Example Questions
Purpose	What problem does this solve? What's the motivation?
Users	Who uses this? What's their context?
Constraints	Any technical limitations? Timeline? Dependencies?
Success	How will you measure success? What's the happy path?
Edge Cases	What shouldn't happen? Any error states to consider?
Existing Patterns	Are there similar features in the codebase to follow?
Non-goals	What is explicitly NOT in scope?

See deep-interview.md for deep interview techniques.

Exit Condition: Continue until the idea is clear OR user says "proceed". Before moving to Phase 2, summarize understanding in 3-5 bullets and confirm with the user.

Phase 2: Explore Approaches

After understanding the idea, propose 2-3 concrete approaches.

Structure for Each Approach:

### Approach A: [Name]

[2-3 sentence description]

**Pros:**
- [Benefit 1]
- [Benefit 2]

**Cons:**
- [Drawback 1]
- [Drawback 2]

**Best when:** [Circumstances where this approach shines]

Guidelines:

• Lead with a recommendation and explain why
• Be honest about trade-offs
• Consider YAGNI--simpler is usually better
• Reference codebase patterns when relevant
• If no approach is accepted after 2 rounds, ask the user to describe their preferred direction directly

Phase 3: Capture the Design

Summarize key decisions in a structured format. For each major component, verify isolation and clarity: it must answer "what does it do, how do you use it, what does it depend on?" and be independently understandable and testable. If working in an existing codebase, note which existing patterns to follow and where targeted improvements fit naturally.

Design Doc: Save to docs/brainstorms/YYYY-MM-DD-<topic>-brainstorm.md. Required sections: What We're Building, Why This Approach, Key Decisions (with rationale), Open Questions, Next Steps. Collapse the Q&A interview log in a <details> block. Include YAML frontmatter with date and topic. Commit to git -- design decisions are project history.

Phase 4: Review and Handoff

Present the design doc to the user for approval. The user explicitly confirming the design is the gate to proceed. When invoked via workflows:brainstorm, the command handles spec review dispatch and next-step orchestration.

Anti-Patterns to Avoid

Anti-Pattern	Better Approach
Asking 5 questions at once	Ask one at a time across dimensions; cluster 2-3 within a dimension
Jumping to implementation details	Stay focused on WHAT, not HOW
Proposing overly complex solutions	Start simple, add complexity only if needed
Ignoring existing codebase patterns	Research what exists first
Making assumptions without validating	State assumptions explicitly and confirm
Creating lengthy design documents	Keep it concise--details go in the plan

Success Criteria

• Design doc saved to docs/brainstorms/YYYY-MM-DD-<topic>-brainstorm.md
• User explicitly approves the spec before handoff to planning
• All open questions resolved or explicitly deferred with rationale

Integration

Brainstorming answers WHAT to build. Planning answers HOW. When brainstorm output exists, workflows:plan detects it and skips idea refinement.

• Next step: workflows:plan (always)
• Predecessor: user request or ambiguous feature description